Interview Puzzles with answers.

Tumblers on a Rotating Table

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<a class="thickbox" href="http://4.bp.blogspot.com/_pxUNdWyjHeo/TJoxkAoDk-I/AAAAAAAAALg/Guj5I6kQxnU/s1600/Four_Tumblers.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Four Tumblers" border="0" height="400" src="http://4.bp.blogspot.com/_pxUNdWyjHeo/TJoxkAoDk-I/AAAAAAAAALg/Guj5I6kQxnU/s400/Four_Tumblers.jpg" title="Four Tumblers" width="320" /></a></div>
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<b><span class="Apple-style-span" style="font-size: x-large;">Tumblers on a Rotating Table Puzzle :</span></b> </div>
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                     A blind gnome and an evil goblin take turns to play a game. Four  tumblers are placed at the corners of a square table. The initial  configuration of the tumblers (facing up or facing down) is chosen by  the evil goblin. When the blind gnome gets his turn, he is allowed to  specify a subset of the four tumblers and flip them simultaneously. To  be precise, he may choose “one tumbler”, “two diagonally opposites”,  “two adjacent”, “three tumblers” or “four tumblers” lying in front of  him, and flip them simultaneously. After flipping, if all four tumblers  are upright, he wins the game! Otherwise, the game continues and the  evil goblin is allowed to rotate the table by an  amount of his choice.  Can the blind gnome win the game with a <i>deterministic</i> strategy?</div>
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<b><span class="Apple-style-span" style="font-size: x-large;">Solution :</span></b></div>
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                      If there were only two cards, then “flip both” — “flip one” — “flip  both” would ensure a victory for the blind gnome. For the case of four  cards, let F denote “all four cards”, A denote “two adjacent cards”, D  denote “two diagonally opposite cards”, O denote “one card”. Then the  following 15-step sequence ensures victory for the blind gnome: F, D, F,  A, F, D, F, O, F, D, F, A, F, D, F. The procedure can be generalized to  2^n cards. This problem is studied in detail by Ehrenborg and Skinner  (see bibliography below); they call it “The Blind Bartender’s Problem”.</div>
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                         A variant of the above problem allows the blind gnome to first  “touch” any t out of n tumblers on a polygonal table with n sides.  Touching allows the gnome to deduce which of the t tumblers he touched  are upright, and then to decide which of these t tumblers to flip. It  was this variant that was originally published in Martin Gardner’s  article in Feb 1979. For four tumblers, the blind gnome can win in five  moves, as Gardner showed in his subsequent article in Mar 1979. The  problem generated quite some interest. Two pairs of mathematicians  independently proved that the blind gnome can win with a deterministic  strategy if and only if t ≥ n(p-1)/p where p is the largest prime factor  of n (Lewis and Willard in 1980; Laaser and Ramshaw 1981). These proofs  are quite involved</div>

Tumblers on a Rotating Table

Tumblers on a Rotating Table Puzzle : A blind gnome and an evil goblin take turns to play a game. Four tumbl...

Mars Rovers thoughtworks puzzles

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<a class="thickbox" href="http://3.bp.blogspot.com/_pxUNdWyjHeo/TIfCXH-xBwI/AAAAAAAAALY/_2vPsiSSOvg/s1600/mars_rover.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Mars rovers" border="0" height="267" src="http://3.bp.blogspot.com/_pxUNdWyjHeo/TIfCXH-xBwI/AAAAAAAAALY/_2vPsiSSOvg/s400/mars_rover.jpg" title="Mars rovers" width="400" /></a></div>
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Mars Rovers is one of the famous puzzle asked by many companies while recruiting people for them. Here the problem is defined and answers are given with Java program.</div>
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<li><a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html#Mars_Rovers_Puzzle">Mars Rovers Puzzle</a></li>
<li><a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html#input">Input</a></li>
<li><a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html#output">Output</a></li>
<li><a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html#input_and_output">Input and Output</a></li>
<li><a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html#solution">Solution</a></li>
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<span class="Apple-style-span" style="font-size: x-large;"><b><a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html" name="Mars_Rovers_Puzzle">Mars Rovers thoughtworks puzzles</a></b></span></div>
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          A squad of robotic rovers are to be landed by NASA on a plateau on Mars. This plateau, which is curiously rectangular, must be navigated by the rovers so that their on-board cameras can get a complete view of the surrounding terrain to send back to Earth.</div>
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          A rover's position and location is represented by a combination of x and y co-ordinates and a letter representing one of the four cardinal compass points. The plateau is divided up into a grid to simplify navigation. An example position might be 0, 0, N, which means the rover is in the bottom left corner and facing North.</div>
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          In order to control a rover, NASA sends a simple string of letters. The possible letters are 'L', 'R' and 'M'. 'L' and 'R' makes the rover spin 90 degrees left or right respectively, without moving from its current spot. 'M' means move forward one grid point, and maintain the same heading.</div>
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Assume that the square directly North from (x, y) is (x, y+1).</div>
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<b><a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html" name="input">INPUT:</a></b></div>
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The first line of input is the upper-right coordinates of the plateau, the lower-left coordinates are assumed to be 0,0.</div>
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The rest of the input is information pertaining to the rovers that have been deployed. Each rover has two lines of input. The first line gives the rover's position, and the second line is a series of instructions telling the rover how to explore the plateau.</div>
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The position is made up of two integers and a letter separated by spaces, corresponding to the x and y co-ordinates and the rover's orientation.</div>
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Each rover will be finished sequentially, which means that the second rover won't start to move until the first one has finished moving.</div>
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<a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html" name="output"><b>OUTPUT:</b></a></div>
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The output for each rover should be its final co-ordinates and heading.</div>
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<b><a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html" name="input_and_output">INPUT AND OUTPUT:</a></b></div>
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<i><b>Test Input:</b></i></div>
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5 5</div>
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1 2 N</div>
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LMLMLMLMM</div>
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3 3 E</div>
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MMRMMRMRRM</div>
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<i><b>Expected Output:</b></i></div>
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1 3 N</div>
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5 1 E</div>
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==========</div>
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<b><a href="http://interviewpuzzle.blogspot.com/2010/09/mars-rovers-thoughtworks-puzzles.html" name="solution">SOLUTION :</a></b></div>
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           Administrator removed the solution. Try your own.</div>
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Mars Rovers thoughtworks puzzles

Mars Rovers is one of the famous puzzle asked by many companies while recruiting people for them. Here the problem is defined and a...

Covent Garden Puzzle

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<b><span style="font-size: large;"><u>Covent Garden Puzzle</u></span></b></div>
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            Mrs. Ram and Mrs. Jones had equal number of apples but Mrs. Jones had larger fruits and was selling hers at the rate of two for a penny, while Mrs. Ram sold three of hers for a penny. </div>
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Mrs. Ram was for some reason called away and asked Mrs. Jones to dispose of her stock. Upon accepting the responsibility of disposing her friend's stock, Mrs. Jones mixed them together and sold them of at the rate of five apples for two pence.</div>
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When Mrs. Ram returned the next day the apples had all been disposed of, but when they came to divide the proceeds they found that they were just seven pence short, and it is this shortage in the apple or financial market which has disturbed the mathematical equilibrium for such a long period.</div>
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Supposing that they divided the money equally, each taking one-half, the problem is to tell just how much money Mrs. Jones lost by the unfortunate partnership? </div>
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<b><span style="font-size: large;"><u>Puzzle Solution</u></span></b> </div>
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             The mixed apples were sold of at the rate of five apples for two pence. So they must have had a multiple of five i.e. 5, 10, 15, 20, 25, 30,…, 60, 65,… etc apples. </div>
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But the minimum number of apples they could have together is 60; so that 30 would have been of Mrs. Ram's that would fetch her 10 (an integer) pence and the other 30 of Mrs. Jones's that would fetch her 15 (also an integer) pence. </div>
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When sold separately it would fetch them 10+15=25 pence altogether. But when sold together it would fetch them 60X2/5=24 pence i.e. a loss of one (25-24=1) pence. </div>
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Since they lost 7 pence altogether; they had altogether 60X7=420 apples that fetched them only 420X2/5=168 pence and they shared 84 pence each of them. But Mrs. Jones could sell her 420/2=210 apples for 210/2=105 pence so she lost "21 pence". </div>
Note: to solve it algebraically:<br />
They lost 7 pence altogether<br />
Suppose each lady has x apples<br />
x/2 + x/3 - 2(2x/5) = 7<br />
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15x + 10x - 24x = 210<br />
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x = 210<br />
Note: Mrs. Johns lost 21 pence.<br />
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But without working Mrs. Ram earned 14 extra pence!<br />
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(84 pence – 210/3 pence = 14 pence).<br />
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Not very fair!<br />
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(Perhaps Mrs. Johns was not very good at math)

Covent Garden Puzzle

Covent Garden Puzzle Mrs. Ram and Mrs. Jones had equal number of apples but Mrs. Jones had larger fruits and was selli...

Einstein’s Puzzle

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<span style="font-size: large;"><b>Puzzle :</b></span><br />
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              Five friends have their gardens next to one another, where they grow three kinds of crops: fruits (apple, pear, nut, cherry), vegetables (carrot, parsley, gourd, onion) and flowers (aster, rose, tulip, lily).</div>
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1. They grow 12 different varieties.<br />
2. Everybody grows exactly 4 different varieties<br />
3. Each variety is at least in one garden.<br />
4. Only one variety is in 4 gardens.<br />
5. Only in one garden are all 3 kinds of crops.<br />
6. Only in one garden are all 4 varieties of one kind of crops.<br />
7. Pear is only in the two border gardens.<br />
8. Paul's garden is in the middle with no lily.<br />
9. Aster grower doesn't grow vegetables.<br />
10. Rose grower doesn't grow parsley.<br />
11. Nuts grower has also gourd and parsley.<br />
12. In the first garden are apples and cherries.<br />
13. Only in two gardens are cherries.<br />
14. Sam has onions and cherries.<br />
15. Luke grows exactly two kinds of fruit.<br />
16. Tulip is only in two gardens.<br />
17. Apple is in a single garden.<br />
18. Only in one garden next to the Zick's is parsley.<br />
19. Sam's garden is not on the border.<br />
20. Hank grows neither vegetables nor asters.<br />
21. Paul has exactly three kinds of vegetable.<br />
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Who has which garden and what is grown where?<br />
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<span style="font-size: large;"><b>Answer : </b></span><br />
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Einstein’s Puzzle

Puzzle : Five friends have their gardens next to one another, where they grow three kinds of crops: fruits (apple, pear, n...

How to interview a person - An Article

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<a class="thickbox" href="http://4.bp.blogspot.com/_pxUNdWyjHeo/THqAY7AwdsI/AAAAAAAAAKo/szr3gJxN5gQ/s1600/how+to+conduct+interview.jpeg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="HR Interview" border="0" src="http://4.bp.blogspot.com/_pxUNdWyjHeo/THqAY7AwdsI/AAAAAAAAAKo/szr3gJxN5gQ/s320/how+to+conduct+interview.jpeg" title="HR Interview questions" /></a></div>
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<u><b><span style="font-size: large;">How to Conduct an Interview</span></b></u></div>
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Interviews have four stages that precede the writing of a story: </div>
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<li><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#a1">Arrangements.</a></li>
<li><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#a2">Preparation.</a></li>
<li><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#a3">The actual interview.</a></li>
<li><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#a4">The reconstruction.</a></li>
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<a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="a1">ARRANGEMENTS</a> <br />
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               Once an interviewer has decided to interview someone, He should call the candidate in advance to make an appointment.  Identify himself by his name and the name of his publication.  If the interviewer feels that he need to do so or asked to describe what the story is about, be brief and general.  The shape of the story might change as him continue his reporting. If the interviewer interviewing several persons in connection with the story, interview the principal person last, because he will be better prepared based on what the learning from the earlier interviews.<br />
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<a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="a2">PREPARATION</a></div>
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            Try to prepare as much research as possible on the person in advance on topic working on. Sources might be the library, public records, the internet and the expert people in that technology for background information.  Prepare the questions in advance if necessary writing and bring them into the interview.  Refer to them but don't show them to the candidate, because it creates too formal an atmosphere.  Ask other questions as they might arise, based on what the candidate says or something new that might come at the moment.  Bring pencil (or pen) and paper.  A stenographer's notebook is usually easier to handle than a large pad but use whatever is comfortable.  Bring a tape recorder but be sure to get the permission to use it from the person you are interviewing.  <br />
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<a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="a3">THE INTERVIEW </a></div>
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            It is inadvisable to launch right into the interview unless it’s being given a few minutes.  Some casual conversation to start with will relax both of you.  Interviewers should ask Questions should be as short as possible.  Give the respondent time to answer.  Interviewers must be a good listener. If candidate prattles on, it is appropriate to move on as politely.  Interviewer might say something such as:  "Fine, but let me ask you this ".  Try to draw out specifics:  How long, how many, when, etc.?  <br />
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          Try to absorb the atmospherics of the locale where the interview takes place, with particular attention to what might be a reflection of the candidate’s personality and interests, such as photos of children or bowling trophies or a paper-littered desk or a clean one, etc.  Note characteristics of the candidate that might be worth mentioning in your story, such as pacing, looking out the window to think, hand gestures and the like.  Invite the person to call you if she/he thinks of anything pertinent after the interview.  It often happens, Interviewer should provide his name, email addresses and phone number on a card or piece of paper before to leave.  If that person has a secretary, be sure to get that person's name and telephone number, too, in case there is some detail that needs follow up and, again, leave information as to how you may be contacted.  If a photo is needed and is not taken during the interview, be sure to make arrangements then to have one taken at a later time.<br />
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<a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="a4"> RECONSTRUCTION </a></div>
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           As soon as it's practical after the interview, find a quiet place to review the handwritten notes.  While taking notes, that may have written abbreviations for words that won't mean anything in a day or two later.  Or some scribbling may need deciphering, and, again, it is more likely to be better able to understand the scribbles soon after the interview.  Underline or put stars alongside quotes that seemed most compelling. One star for a good quote, two stars for a very good one, etc.   It will speed the process when you get to the writing stage.  One other thing to look for in the notes:  the quote wrote down might not make a lot of sense, unless to remember what specific question it was responding to.  In short, fill in whatever gaps exist in the notes that will help better understand them when writing.</div>
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<u><span style="font-size: large;"><b>How to Interview a Programmer</b></span></u></div>
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<i><b>Finding good programmers is hard because good programming is dependent on much more than just knowledge of programming language syntax. </b></i></div>
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         1.  The Interviewer needs someone who, despite wearing striped pants with a polka dot shirt, has a good sense of taste in OO design. <br />
        2.  He need someone who the candidate is creative enough to find innovative solutions to problems, yet anal retentive enough to always line up their curly braces. <br />
        3. The Interviewer needs someone who (the Programmer) is humble enough to be open to suggestions for improvement, but arrogant enough to stand firm and provide leadership when they are the best person to provide it.<br />
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<i><b>How to tell all this about a stranger by spending 30 minutes with them in a conference room? </b></i><br />
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<b>Summery:</b><br />
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 <a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#b1">Explore an Area of Expertise </a><br />
 <a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#b2">Have Them Critique Something</a><br />
 <a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#b3">Ask Them to Solve a Problem</a><br />
 <a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#b4">Look at Their Code</a><br />
 <a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#b5">Ask About a People Problem</a><br />
 <a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#b6">Get to Know Them</a><br />
 <a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html#b7">Conclusion</a><br />
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<b><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="b1">Explore an Area of Expertise</a></b><br />
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Rather than simply look for expertise and experience in the exact area in which the candidate will work, it is necessary look for general programming talent and ability. One way to explore and judge a candidate's talents is to explore an area of their expertise: <br />
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<li>Hire for talent. One of the biggest mistakes companies make is to recruit from a shopping list: I need a programmer with six years Java, three years Oracle, and two years EJBs. The world changes, so to hire folks who change with it. Look for people who know computing, not necessarily particular narrow niches. Not only will they adapt better in the future, they're also more likely to be innovative in the present.  </li>
<li> To identify how good the candidates are technically, I let them choose an area in which they feel they have expertise. I need them to know something well, and I ask them about that. I ask them why. I want them to know why something in their area of expertise works the way it does. I'm not necessarily after an expert in the area I need. If they learned why in the past, I have confidence they'll learn why in the future. </li>
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<b><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="b2">Have Them Critique Something</a></b><br />
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Another technique involves the importance of creating a dialog with the candidate. To get to know the candidate's talents and personality, Do n’t merely ask questions that have short factual answers. Find a way to engage a conversation. To stimulate dialog, ask the candidate to critique some technology: <br />
<ol>
<li>I ask candidates to critique a system or platform that we both have in common, preferably something they will use on the job. For example, I might ask, "What parts of Java don't you like and why?" </li>
<li>I give candidates samples of our current code and ask them to explain and critique it. This gives me a sense of their skills, but also lets them know what they can expect. </li>
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<b><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="b3">Ask Them to Solve a Problem</a></b><br />
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Another way to foster an open-ended dialog is to ask the candidate to perform a task: to solve a problem or create a design. Although everyone at the meeting seemed to agree that this was important and useful technique, it also generated a lot of concern. People felt that asking the candidate to solve puzzles and problems needed to be done with care:<br />
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Several expertise interview taken and their review is given below<br />
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<li>I like to ask a candidate to solve a small-scale design problem, finger exercises, to see how they think and what their process is: "How would you write a function that tells me if its argument is a power of 2?" I'm not looking for the optimal bit-twiddling solution ((n & -n) == n). I'm looking to see if they get the method signature right, if they think about boundary cases, if their algorithm is reasonable and they can explain its workings, and if they can improve on their first attempt. </li>
<li>I ask candidates to create an object model of a chicken. This eliminates any problems with uncertainties about the problem domain, because everyone knows what a chicken is. I think it also jars people away from the technical details of a computer. It tests to see if they are capable of thinking about the big picture. </li>
<li>I hate anything that asks me to design on the spot. That's asking to demonstrate a skill rarely required on the job in a high-stress environment, where it is difficult for a candidate to accurately prove their abilities. I think it's fundamentally an unfair thing to request of a candidate. </li>
<li>I don't like when I'm asked to write a program that does X on a piece of paper. Don't ask the candidate to write a program on paper. That is a waste of time and sweat. People don't write software on paper, they do it with computers using auto-completion, macros, indexed API documentation, and context-sensitive help. They think about it, refractor it, and even rewrite it. If you want to see a person's work, ask them to write some small module or implement some interface before the interview and bring the code on a notebook PC or on hard copy. Then you can review it and discuss the design, coding style, and decisions that went into it. This will give you a much more realistic and useful assessment of a person's work and style. </li>
<li>I like design dialog questions that don't have a single fixed answer. That way they have to ask me questions, and this sparks a discussion. It's good to have a whiteboard available in the room. A dialog lets the interviewer see how the interviewee works, whereas a question of fact is just that: it is great for TV quiz shows, but doesn't tell you how someone will work and approach things over time. A puzzle question requires knowing a trick, which is in essence something that is either known or unknown. I dislike puzzle questions, because they don't require dialog. </li>
<li>What constitutes a reasonable question depends a lot on the candidate's experience and maturity. </li>
<li>I look for people with curiosity. Present problems, not puzzles. </li>
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<b><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="b4">Look at Their Code</a></b><br />
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          One technique we all seemed to like: Have the candidate bring a code portfolio to the interview. Look at the candidate's code and talk to them about it. Although we were concerned that some candidates may not have code they could legally bring to the interview, we figured most candidates could probably come up with something. It can't hurt at least to ask a candidate to bring to the interview a sample of code they had written in the past. <br />
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         Find Out What Books They Read Several people indicated that they ask candidates about the programming books they read to see if a programmer is self-motivated or concerned about improving their own programming skills:<br />
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<b><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="b5">Ask About a People Problem</a></b><br />
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            As important as technical ability, or perhaps more important, is personality. How well would the candidate fit the team? How well would they fit the work environment? People used various techniques to judge personality. Good citizenship is probably more important than technical prowess, because if you have people with the right kind of attitude and demeanor, you can help them gain the technical knowledge and software development habits. But if you have people who lack humility and maturity, it can be extremely difficult to get them to cooperate in reaching a goal, no matter how bright they are or what they've accomplished in the past. <br />
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<b><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="b6">Get to Know Them</a></b><br />
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          Perhaps the prominent theme of our discussion was that you need to try to get to know the candidate as best you can. Talk to the candidate in the interview. Try to get a feel for them. If possible, bring them in on a trial basis or for a probationary period. That would give you more time to get to know the candidate, and give the candidate more time to get to know you:<br />
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<i>Chuck Allison:</i> I talk to them. I get a feel for them. I always ask about what they've done. I have found that by discovering what a person is excited about technically, you can learn a lot of important things about them. In the past I've asked people to describe a project that was especially interesting to them, or that was challenging and successful. On occasion I've asked what they've done that they're the most proud of. This usually reveals the depth of one's understanding and mastery. It also gets them to turn on the fire hose verbally, and you can sit back and get most of the answers you need.<br />
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<i>Randy Stafford: </i>I look at past projects listed on their resume, and ask them to talk about those projects—how was the team organized, what the technologies and architectures were used, was the software successful in production, etc. In their answers I'm listening for what lessons they learned from those experiences, and whether those lessons match with lessons I've learned from my experiences and from professional literature. I get a glimpse into how they perceive themselves in relation to the world around them. Some come off as arrogant, some ignorant, some helpless. Others sound humble, intelligent, and motivated. I often ask them what software development literature they read. Continuous education is very important to me.<br />
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<i>Angelika Langer: </i>In Germany, hiring is like marrying someone. It's "until death do us part"—a marriage without the backdoor of a divorce, because you can't fire employees. The only chance for firing someone is during a three- to six-month probationary period, or when the company goes out of business. The major filtering is done before the interview, based on the curriculum vitae (CV) and submitted papers, such as evaluations from former employers. (In Germany, employers must provide every employee with a written evaluation when they leave the company.) The interview itself is usually brief. The main tool in filtering is scrutinizing the CV and papers; 98 percent of all applicants are disqualified in this phase. The interview should confirm the impression you gain from the applicant's papers and allows you to sense their personality. The lucky winner then goes on a probationary period. Probation definitely does not replace the filtering; it just keeps a last exit open until you really must commit.<br />
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<i>Andy Hunt: </i>We've hired people who interviewed well, but they were terrible at the job. If possible, hire them in for a trial period.<br />
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<i>Dawn McGee: </i>You could also bring candidates in for half a day, and have them do what they would be doing on the job.<br />
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<b><a href="http://interviewpuzzle.blogspot.com/2010/08/how-to-conduct-interview.html" name="b7">Conclusion</a></b><br />
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             To sum up the overlying themes from our hour-long discussion in Portland: You should look for talent and fit more than specific skill sets. Ask open-ended questions to initiate revealing dialog. Ask candidates to critique something. Ask them to design something. Investigate their past experience. Review their code. And through conversation and, if possible, a trial period, you should try to become familiar with the candidate's technical abilities, talents, and personality. <br />
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How to interview a person - An Article

How to Conduct an Interview Interviews have four stages that precede the writing of a story: Arrangements. Preparation. ...

Poisened Drink Puzzle

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<a class="thickbox" href="http://3.bp.blogspot.com/_pxUNdWyjHeo/TH3a2xU8yxI/AAAAAAAAAKw/1gQA-uXjbOg/s1600/scotch.jpeg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Poisened Drink" border="0" height="320" src="http://3.bp.blogspot.com/_pxUNdWyjHeo/TH3a2xU8yxI/AAAAAAAAAKw/1gQA-uXjbOg/s320/scotch.jpeg" title="Poisened Drink" width="239" /></a></div>
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<b>Poisened Drink Puzzle</b></div>
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                     A rich old man has died. After his  death, his children are surprised to learn that he has left all of his  money to his oldest son Jeremiah, who loved him dearly, and ignored his  other children, who hated him. </div>
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                  So,  the funeral is a day or two later, and the other sons and daughters  have decided to kill Jeremiah and take his inheritance. Since his  father's death, Jeremiah has taken to drinking, and they know that, at  the wake, he's going to be gulping down the liquor like it was nectar of  the gods. So they decide to poison the drinks. One of the other sons,  Wallace, tends bar, and gets the poison all ready. So  Jeremiah comes up, crying and depressed, and orders a scotch on the  rocks. Wallace serves him one, and he chugs it down in two seconds.  "Give me another." Wallace gives him a second glass of scotch, which he  also drinks in a matter of moments. The other siblings are puzzled...the  poison is fast-acting; Jeremiah should be convulsing on the floor and  retching his guts out. Finally, fifteen minutes later, a rather  inebriated and very much alive Jeremiah orders one last glass of scotch,  but as Wallace hands it to him, he changes his mind and leaves,  sobbing. The other siblings come over to Wallace, and wonder what's  going on. They talk about what could have gone wrong for a few minutes,  and figure the poison's harmless. So Wallace sips the drink he poured  for Jeremiah, and is pronounced DOA thirty minutes later. </div>
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Why did Jeremiah live? (He had no immunity to the poison, he didn't know it was coming, and the poison was obviously deadly.)<br />
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<b>Answer :</b><br />
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          <span style="font-size: small;">Jeremiah orders a scotch on the rocks (ice  cubes). Dropping the poison into his drink, it lands on top of the ice  cubes. Jeremiah downs his two drinks very quickly, not giving enough  time for the poison to mix with his drink. Conversely, the brother waits  a "few minutes" before drinking, allowing the ice cubes to melt and  giving ample time for the poison to mix with the scotch. He is soon dead  as a result!  </span></div>

Poisened Drink Puzzle

Poisened Drink Puzzle A rich old man has died. After his death, his children are surprised to learn tha...

Four ships Puzzle

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<a class="thickbox" href="http://3.bp.blogspot.com/_pxUNdWyjHeo/THnmYAGvD-I/AAAAAAAAAKI/J_zAbRvw3mU/s1600/DCL4ShipsSmaller.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="four ships" border="0" src="http://3.bp.blogspot.com/_pxUNdWyjHeo/THnmYAGvD-I/AAAAAAAAAKI/J_zAbRvw3mU/s320/DCL4ShipsSmaller.jpg" title="four ships" /></a></div>
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<span style="font-size: large;"><b>Puzzle :</b></span><br />
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Four ships are sailing on a 2D planet in four different directions. Each ships traverses a straight line at constant speed. No two ships are traveling parallel to each other. Their journeys started at some time in the distant past. Sometimes, a pair of ships collides. A ship continues its journey even after a collision. However, it is strong enough only to survive two collisions; it dies when it collides a third time. The situation is grim. Five of six possible collisions have already taken place (no collision involved more than 2 ships) and two ships are out of commission. What fate awaits the remaining two?</div>
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Let z-axis denote time. let x- and y- axes denote the 2D planet. Then the four trajectories are straight lines. Since no collision involved more than two ships, these four lines must all lie in a plane. So, one might be tempted to believe that the two other ships will also collide. But, they might have collided in negative time. So, it cannot be decided from the given information that the two ships will collide or not?<br />
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This can be made clearer through the following two diagrams. In the first one, the four ships move such that there is no collision between the two ships. In the other diagram, the four ships move such that there is a collision between them.</div>

Four ships Puzzle

Puzzle : Four ships are sailing on a 2D planet in four different directions. Each ships traverses a straight line at constant speed. N...

Three Boxes and a Ruby Puzzle with Solution

Three Boxes and a Ruby Puzzle with Solution

Puzzle : Alice places three identical boxes on a table. She has concealed a precious ruby in one of them. The other tw...

Eight Queens Puzzle

<div style="text-align: center;"><u><span style="font-size: large;"><b>Eight Queens Puzzle</b></span></u></div><div style="text-align: justify;"><br />
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</div><div style="text-align: justify;">The eight queens puzzle is the problem of placing eight chess queens  on an 8×8 chessboard such that none of them are able to capture any other using the standard chess queen's moves. </div><div style="text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_pxUNdWyjHeo/TGg2kUM1T0I/AAAAAAAAAJg/nCV3lxP0Ysk/s1600/TitleBoard.jpg" class="thickbox" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/_pxUNdWyjHeo/TGg2kUM1T0I/AAAAAAAAAJg/nCV3lxP0Ysk/s320/TitleBoard.jpg" /></a></div><div style="text-align: justify;"><br />
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 Available movement of the Queen is shown in above picture. The queens must be placed in such a way that no two queens attack each other. In chess, a queen can move as far as horizontally, vertically, or diagonally. The standard 8 by 8 Queen's problem asks how to place 8 queens on an ordinary chess board so that none of them can hit any other in one move.<br />
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<embed bgcolor="#000000" height="510" pluginspage="http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash" quality="high" src="http://tszone.co.cc/8Queens.swf" type="application/x-shockwave-flash" width="760"></embed><br />
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This puzzle has <u><b>twelve unique solution</b></u>. The following image show one solution as using backtracking algorithm method. See <a href="http://en.wikipedia.org/wiki/Eight_queens_puzzle">wikipedia </a>for more details about 8 Queen puzzle.<br />
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<span id="goog_1006611189"></span><span id="goog_1006611190"></span><br />
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<u><span style="font-size: large;"><b>Algorithms :</b></span></u><br />
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Check the following links <br />
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1. <a href="http://www.mactech.com/articles/mactech/Vol.13/13.12/TheEightQueensProblem/%20">http://www.mactech.com/articles/mactech/Vol.13/13.12/TheEightQueensProblem/ </a><br />
2. <a href="http://yuval.bar-or.org/index.php?item=9">http://yuval.bar-or.org/index.php?item=9</a><br />
3. <a href="http://firefang.net/english/n-queens">http://firefang.net/english/n-queens</a><br />
4. <a href="http://bridges.canterbury.ac.nz/features/eight.html">http://bridges.canterbury.ac.nz/features/eight.html</a><br />
5. <a href="http://mathworld.wolfram.com/QueensProblem.html">http://mathworld.wolfram.com/QueensProblem.html</a><br />
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for algorithm to solve this problem.<br />
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<u><span style="font-size: large;"><b>Source Code :</b></span></u><br />
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The solved java program is available here.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">1. <a href="http://tszone.co.cc/NQueens.java">http://tszone.co.cc/NQueens.java</a></div><div style="text-align: justify;">2. <a href="http://rooparam.blogspot.com/2009/12/eight-queens-solution-with-dfs-using.html">http://rooparam.blogspot.com/2009/12/eight-queens-solution-with-dfs-using.html</a></div>

Eight Queens Puzzle

Eight Queens Puzzle The eight queens puzzle is the problem of placing eight chess queens on an 8×8 chessboard such that none of them are ...

Hats and IIT students

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<span style="font-size: large;"><b>Puzzle:</b></span></div>
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This is another hats puzzle same like as <a href="http://interviewpuzzle.blogspot.com/2010/05/prisoners-and-hats-puzzle.html">prisoners and hats puzzle</a>. The puzzle is Nine IIT students were sitting in a classroom. Their professor wanted them to test. Next day the professor told all of his 9 students that he has 9 hats, The hats either red or black color. He also added that he has at least one hat with red color and the no. of black hats is greater than the no. of red hats. The professor keeps those hats on their heads and ask them tell me how many red and black hats the professor have? Obviously students can not talk to each other or no written communication, or looking into each other eyes; no such stupid options and no tricks.</div>
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Professor goes out and comes back after 20 minutes but nobody was able to answer the question. So he gave them 10 more minuets but the result was the same. So he decides to give them final 5 minutes. When he comes everybody was able to answer him correctly.</div>
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So what is the answer? and why? </div>
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<b><span style="font-size: large;">Answer :</span></b></div>
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After 20 minutes :<br />
Lets assume that their is 1 hat of red color and 8 hats of black color.  The student with red hat on his head can see all 8 black hats, so he  knows that he must be wearing a red hat.<br />
Now we know that after first interval nobody was able to answer the prof that means our assumption is wrong. So there can not be 1 red and 8 black hats.<br />
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After second interval of 10 minutes :<br />
Assume that their are 2 hats of red color and 7 hats of black color. The  students with red hat on their head can see all 7 black hats and 1 red  hat, so they know that they must be wearing a red hat.<br />
Now we know that after second interval nobody was able to answer the prof that means our assumption is again wrong. So there can not be 2 red and 7 black hats.</div>
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After third interval of final 5 minutes :<br />
Now assume that their is 3 hats of red color and 6 hats of black color.  The students with red hat on their head can see all 6 black hats and 2  red hats, so they know that they must be wearing a red hat.<br />
Now we know that this time everybody was able to answer the prof that means our assumption is right. <br />
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So there are 3 red hats and 6 black hats. <br />
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Now as everybody gave the answer so there can be a doubt that only those 3 students know about it how everybody came to know ?<br />
Then here is what i think, the professor gave them FINAL 5 minutes to  answer, so other guys will think that the professor expects the answer  after 3rd interval (according to prof it must be solved after 3  intervals), so this is the clue for others.   </div>

Hats and IIT students

Puzzle: This is another hats puzzle same like as prisoners and hats puzzle . The puzzle is Nine IIT students were sitti...

Engineers and Managers Puzzle

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<a href="http://4.bp.blogspot.com/_pxUNdWyjHeo/TGQpJ5sOq9I/AAAAAAAAAJQ/8am6_pCo3zM/s1600/ANZ-Bank-counter.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/_pxUNdWyjHeo/TGQpJ5sOq9I/AAAAAAAAAJQ/8am6_pCo3zM/s320/ANZ-Bank-counter.jpg" /></a></div>
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<u><span style="font-size: large;">Engineers and Managers Puzzle</span></u></div>
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<span style="font-size: large;"><b>Puzzle :</b></span><br />
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         In a city, The police has surrounded the Bank. There are 50 people in the building. Each person is either an engineer or a manager of the bank. All computer files have been deleted, and all documents have been shredded by the managers. The problem confronting the police is to separate the people into these two classes, so that all the managers are locked in a room  and all the engineers are freed. every people knows the status of all others. The interrogation consists entirely of asking person i if person j is an engineer or a manager. The engineers always tell the truth. What makes it hard is that the managers may not tell the truth. In fact, the managers are evil geniuses who are conspiring to confuse the interrogators.<br />
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   1. Under the assumption that more than half of the people are engineers, can you find a strategy for the Police to find one engineer with at most 49 questions?<br />
   2. Is this possible in any number of questions if half the people are managers?<br />
   3. Once an engineer is found, he/she can classify everybody else. Is there a way to classify everybody in fewer questions?</div>
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<b><span style="font-size: large;">Answer :</span></b></div>
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Part 1: <br />
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Here's an n-1 query solution to part 1. Maintain three sets of people: UNSEEN, STACK, and DISCARD. Initialize the process by picking one arbitrarily to be the STACK, everything else is UNSEEN. Repeat the following step until UNSEEN is empty:<br />
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    Pick an UNSEEN element x, remove it from UNSEEN. Ask the top of the STACK y about x. If y says "manager" pop y off the stack and DISCARD both x and y. If it says "engineer" add x to the top of the STACK.<br />
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After all elements have been processed in this way (n-1 comparisons), the top of the stack must be an engineer.<br />
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Why does this work? First observe that whenever we discard a pair, at least one of them is a manager. So among the rest of them (STACK and UNSEEN) a majority must still be engineers. So at the end, when UNSEEN is empty, there must be an engineer in the stack, therefore the top of the stack must be an engineer.<br />
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This can be improved to 48 simply by stopping one earlier. When there's one UNSEEN left, if the stack is empty, that UNSEEN one is an engineer. Otherwise, the top of the stack must be an engineer.<br />
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first step we can just throw out one person, and appy this algorithm to the remaining 49 obtaining 47 comparisons. This gives the optimal algorithm.<br />
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This is optimal. The proof appears in the solution of homework assignment 7 of Steven Rudich's course 15-251 taught at CMU in the spring semester of 2002. See Solution 7.<br />
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Part 2: If half or more of the people are managers, then the problem cannot be solved. The managers can ensure this simply by always lying. Now there's way to separate the two sets of people. Each one simply claims the others are Managers.<br />
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Part 3: I don't know any better solution than to simply using the solution to Part 1 to identify everybody.<br />
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Engineers and Managers Puzzle

Engineers and Managers Puzzle Puzzle : In a city, The police has surrounded the Bank. There are 50 people in the buildin...

Lateral Thinking Puzzles

<div style="text-align: justify;">Puzzle 1:</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">A man is trapped in a room. The room has only two possible exits: two doors. Through the first door there is a room constructed from magnifying glass. The blazing hot sun instantly fries anything or anyone that enters. Through the second door there is a fire-breathing dragon. How does the man escape?</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Answer : </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">He waits until night time and goes out the first door.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Puzzle 2:</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">In a far away land, it was known that if you drank poison, the only way to save yourself is to drink a stronger poison, which neutralizes the weaker poison. The king that ruled the land wanted to make sure that he possessed the strongest poison in the kingdom, in order to ensure his survival, in any situation. So the king called the kingdom's pharmacist and the kingdom's treasurer, he gave each a week to make the strongest poison. Then, each would drink the other one's poison, then his own, and the one that will survive, will be the one that had the stronger poison.<br />
The pharmacist went straight to work, but the treasurer knew he had no chance, for the pharmacist was much more experienced in this field, so instead, he made up a plan to survive and make sure the pharmacist dies. On the last day the pharmacist suddenly realized that the treasurer would know he had no chance, so he must have a plan. After a little thought, the pharmacist realized what the treasurer's plan must be, and he concocted a counter plan, to make sure he survives and the treasurer dies. When the time came, the king summoned both of them. They drank the poisons as planned, and the treasurer died, the pharmacist survived, and the king didn't get what he wanted.<br />
What exactly happened there?</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Answer :</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The treasurer's plan was to drink a weak poison prior to the meeting with the king, and then he would drink the pharmacist's strong poison, which would neutralize the weak poison. As his own poison he would bring water, which will have no effect on him, but the pharmacist who would drink the water, and then his poison would surely die. When the pharmacist figured out this plan, he decided to bring water as well. So the treasurer who drank poison earlier, drank the pharmacist's water, then his own water, and died of the poison he drank before. The pharmacist would drink only water, so nothing will happen to him. And because both of them brought the king water, he didn't get a strong poison like he wanted.</div>

Lateral Thinking Puzzles

Puzzle 1: A man is trapped in a room. The room has only two possible exits: two doors. Through the first door there is a room constructed f...

The Gold Chain -Interview Puzzle

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<a href="http://2.bp.blogspot.com/_pxUNdWyjHeo/TF6SLyB6XCI/AAAAAAAAAIo/nCviLcyTdqg/s1600/m4s2-chain.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="The gold chain" border="0" src="http://2.bp.blogspot.com/_pxUNdWyjHeo/TF6SLyB6XCI/AAAAAAAAAIo/nCviLcyTdqg/s320/m4s2-chain.gif" title="The gold chain" /></a></div>
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<span style="font-size: large;"><b><span style="font-family: Courier New,Courier;">The Gold Chain - Puzzle :</span></b></span><br />
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<b><span style="font-family: Courier New,Courier;">         </span></b><span style="font-family: Courier New,Courier;">A woman wants to buy a painting at an auction where you bid grams of gold instead of money.  She owns a gold chain made of 23 interlocking loops, each weighing 1 gram.  She wants to go to a jeweler before the auction to cut the minimum number of loops that would allow her to pay any sum from 1 to 23.  For example, she could pay a 13 gram price with a 12 link chain and a single link.  After much thought, she figures out a way to do it by cutting just 2 of the loops in the chain.  How many loops are in the pieces of chains that she has after the 2 cuts?</span></div>
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<span style="font-size: large;"><b>Answer : </b></span></div>
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Make a cut in 4 th and loops of the Gold chain so you can get pieces of 1,1,3,6 and 12. from this you can weights from 1 to 23 grams.</div>
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The Gold Chain -Interview Puzzle

The Gold Chain - Puzzle : A woman wants to buy a painting at an auction where you bid grams of gold instead of money. ...

Dragon and Knight - Trilogy interview puzzle

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<a href="http://3.bp.blogspot.com/_pxUNdWyjHeo/TF6PBAN2NrI/AAAAAAAAAIg/8hIPuoj7ZkQ/s1600/the-dragon-knight-fantasy.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Dragon and Knight " border="0" height="300" src="http://3.bp.blogspot.com/_pxUNdWyjHeo/TF6PBAN2NrI/AAAAAAAAAIg/8hIPuoj7ZkQ/s400/the-dragon-knight-fantasy.jpg" title="Dragon and Knight " width="400" /></a></div>
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<span style="font-size: large;"><b>Dragon and Knight - Trilogy interview puzzle</b></span><br />
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       This is another one famous puzzle asked in many interview puzzle. This was asked in Trilogy interview. </div>
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Lets consider a dragon and knight live on an island. That island has seven poisoned  wells, which is numbered 1 to 7. If you drink from a well, you can only save  yourself by drinking from a higher numbered well. The Well whose is number 7 is located at  the top of a high that mountain, so only the dragon can reach it.<br />
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One day they decide that the island isn't big enough for the two of  them, and they have a duel. Each of them brings a glass of water to the  duel, they exchange glasses, and drink. After the duel, the knight lives  and the dragon dies.<br />
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Why did the knight live? Why did the dragon die?</div>
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<span style="font-size: large;"><b>Answer :</b></span><br />
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              Dragon knows that knight cant reach well 7. So he thinks that if i give  knight water from well 6 or 7, knight would die for sure. So he would  get water from well 6 or 7 for knight.<br />
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Knight knew that no matter from which well he gives the water, dragon  will go and drink from well 7 and live. So he got normal water for  dragon and before duel drank water from well 1. <br />
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When they exchanged glasses and drank water, dragon rushed to well 7 and  drank poison from it, thinking that it would cure the poison he just  drank (but he drank normal water), so dragon died. Knight on the other  hand already had poison from well 1 so what dragon gave him effectively  cured him. So he lived.</div>
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comments if you have any other answers..</div>
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Dragon and Knight - Trilogy interview puzzle

Dragon and Knight - Trilogy interview puzzle This is another one famous puzzle asked in many interview puzzle. This was asked i...

Blue-eyed Samurais Puzzle

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<span style="font-size: large;"><b>Puzzle :</b></span><br />
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           A remote island contains a tribe whose members have either blue or brown eyes. Tribe members do not know the color of their eyes and if they learn it, they must kill themselves the same night. Every member of the tribe always behaves logically. So one day, a sailor visits the island and makes an observation that at least one of the members of the tribe has blue eyes. On the 10th night after that, all people with blue eyes kill themselves. How many blue-eyed people were there in the tribe?</div>
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 <b><span style="font-size: large;">Solution :</span></b></div>
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           Ten. The logic goes as follows. If there were only one person with blue eyes on the island, then he would see that no one else has blue eyes and will kill himself on the first night. If there were two people with blue eyes, then one of the people with blue eyes would see that the second blue-eyed person did not kill himself on the first night, leading him to conclude that since he sees no one else with blue eyes, he must be one of them and will kill himself on the second night. The other blue-eyed person will follow the same logic and also kill himself on the second night. The same idea applies to the rest of the problem.</div>
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Comments if you have any other answers </div>

Blue-eyed Samurais Puzzle

Puzzle : A remote island contains a tribe whose members have either blue or brown eyes. Tribe members do not know the c...

Image Puzzles with Answers

Puzzle Images<br />
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Image Puzzles with Answers

Puzzle Images 1. 2. 3. 4. 5.

Infosys Interview puzzles with answers

<div style="text-align: center;"><span style="font-size: large;"><b>Logical Puzzles </b></span></div><div style="text-align: center;"><br />
</div><div style="text-align: justify;">1.  A clock with the hours round the face in Roman block numbers, as illustrated in the sketch fell down and the dial broke into four parts. The numerals in each part in every case summed to a total of 20. Can you show how the four parts of the clock face was broken?<br />
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2. Shown in the sketch are 6 matches. Can you rearrange them to make nothing? <br />
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3.  Here is a sketch: Can you rearrange the position of the numbers 1 to 10 so that the sum of any two adjacent numbers is equal to the sum of the pair of numbers at the opposite ends of the diameter?<br />
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4. Can you place 10 coins in such a way that they lie in 5 straight lines and on each line there are 4 coins. There are at least two solutions.<br />
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</div>5. Nine dots are arranged by 3 rows of 3 in the form of a square as shown in the sketch below:<br />
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Can you draw 4 straight lines, the second beginning where the first ends, the third beginning where the second ends and the fourth beginning where the third ends so that each dot is or at least one line?<br />
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<div style="text-align: center;"><span style="font-size: large;"><b>Answers</b></span></div><div style="text-align: center;"><br />
</div><div style="text-align: left;">1.   <span id="goog_697837821"></span><span id="goog_697837822"></span></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_pxUNdWyjHeo/TFxObcjm9QI/AAAAAAAAAHI/hbfGtP_Qf_w/s1600/11.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/_pxUNdWyjHeo/TFxObcjm9QI/AAAAAAAAAHI/hbfGtP_Qf_w/s320/11.PNG" /></a></div><div style="text-align: left;"><br />
</div><div style="text-align: left;">2.</div><div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_pxUNdWyjHeo/TFxOcFyilrI/AAAAAAAAAHQ/bEbXvBkf1Bw/s1600/21.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/_pxUNdWyjHeo/TFxOcFyilrI/AAAAAAAAAHQ/bEbXvBkf1Bw/s320/21.PNG" /></a></div><div style="text-align: left;"><br />
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</div><div style="text-align: left;">3.</div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_pxUNdWyjHeo/TFxOc3rFx2I/AAAAAAAAAHY/Vvb-LE3NNL8/s1600/31.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/_pxUNdWyjHeo/TFxOc3rFx2I/AAAAAAAAAHY/Vvb-LE3NNL8/s320/31.PNG" /></a></div><div style="text-align: left;"><br />
</div><div style="text-align: left;">4.</div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_pxUNdWyjHeo/TFxOd2MFGoI/AAAAAAAAAHg/VWcWRnseJ0Y/s1600/41.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/_pxUNdWyjHeo/TFxOd2MFGoI/AAAAAAAAAHg/VWcWRnseJ0Y/s320/41.PNG" /></a></div><div style="text-align: left;">5.</div><div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_pxUNdWyjHeo/TFxOeaLLs_I/AAAAAAAAAHo/XfvCdtARLek/s1600/51.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/_pxUNdWyjHeo/TFxOeaLLs_I/AAAAAAAAAHo/XfvCdtARLek/s320/51.PNG" /></a></div><div style="text-align: left;"><br />
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Infosys Interview puzzles with answers

Logical Puzzles 1. A clock with the hours round the face in Roman block numbers, as illustrated in the sketch fell down and the dial broke...

Old Lady and her Eggs - Puzzle

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<span style="font-size: large;"><b>Old Lady and her Eggs</b> </span>- Puzzle<br />
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This puzzle can be solved based on simple math tactics.. <br />
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<b>Puzzle</b> : <br />
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             Once upon a time, There was an old lady has more number of eggs. She went to sell her vast quantity of eggs at the local market.<br />
When a small boy asked how many she had, she replied:<br />
Son, I can't count past 100 but I know that.<br />
If you divide the number of eggs by 2 there will be one egg left.<br />
If you divide the number of eggs by 3 there will be one egg left.<br />
If you divide the number of eggs by 4 there will be one egg left.<br />
If you divide the number of eggs by 5 there will be one egg left.<br />
If you divide the number of eggs by 6 there will be one egg left.<br />
If you divide the number of eggs by 7 there will be one egg left<br />
If you divide the number of eggs by 8 there will be one egg left.<br />
If you divide the number of eggs by 9 there will be one egg left.<br />
If you divide the number of eggs by 10 there will be one egg left.<br />
Finally. If you divide the Number of eggs by 11 there will be NO EGGS left.<br />
How many eggs did the old lady have?

Old Lady and her Eggs - Puzzle

Old Lady and her Eggs - Puzzle This puzzle can be solved based on simple math tactics.. Puzzle : Once upon a time, T...

Einstein’s Riddle

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<b><span style="font-size: large;">Einstein's Riddle - Interview puzzles</span></b><br />
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Einstein said that only 2% of the world could solve this problem. There are 5 houses in 5 different colors. In each house lives a person with a different nationality. The 5 owners drink a certain type of beverage, smoke a certain brand of cigar, and keep a certain pet. No owners have the same pet, smoke the same brand of cigar, or drink the same beverage. <br />
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<b>Hints:</b><br />
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· The Brit lives in the red house.<br />
· The Swede keeps dogs as pets.<br />
· The Dane drinks tea.<br />
· The green house is on the left of the white house.<br />
· The green homeowner drinks coffee.<br />
· The person who smokes Pall Mall rears birds.<br />
· The owner of the yellow house smokes Dunhill.<br />
· The man living in the center house drinks milk.<br />
· The Norwegian lives in the first house.<br />
· The man who smokes Blend lives next to the one who keeps cats.<br />
· The man who keeps the horse lives next to the man who smokes Dunhill.<br />
· The owner who smokes Bluemaster drinks beer.<br />
· The German smokes prince.<br />
· The Norwegian lives next to the blue house.<br />
· The man who smokes Blend has a neighbor who drinks water.<br />
Who owns the fish?

Einstein’s Riddle

Einstein's Riddle - Interview puzzles Einstein said that only 2% of the world could solve this problem. There are 5 houses in 5 ...

Image puzzles with Answers - II

<strong><span style="font-size: large;">Image puzzles with Answers</span></strong> <br />
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                This puzzles are based on the images we need to find out the phrase. It shows the our identification based on the images. This is same as like the puzzles available in <a href="http://interviewpuzzle.blogspot.com/2010/05/image-puzzles-with-answers.html">Image puzzles with Answers</a>. The images are given below.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_pxUNdWyjHeo/TDWz4oKa2-I/AAAAAAAAAFw/hkS1Z00kOlU/s1600/1.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="104" rw="true" src="http://4.bp.blogspot.com/_pxUNdWyjHeo/TDWz4oKa2-I/AAAAAAAAAFw/hkS1Z00kOlU/s640/1.PNG" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"><br />
</div><div class="separator" style="clear: both; text-align: left;">2.<a href="http://4.bp.blogspot.com/_pxUNdWyjHeo/TDWz5Ob44aI/AAAAAAAAAF4/hUOQOQ8VgG0/s1600/2.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="110" rw="true" src="http://4.bp.blogspot.com/_pxUNdWyjHeo/TDWz5Ob44aI/AAAAAAAAAF4/hUOQOQ8VgG0/s640/2.PNG" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"><br />
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</div><div class="separator" style="clear: both; text-align: left;">5.</div><div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_pxUNdWyjHeo/TDWz8NwWXmI/AAAAAAAAAGQ/YKIk3CIUazc/s1600/5.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" rw="true" src="http://2.bp.blogspot.com/_pxUNdWyjHeo/TDWz8NwWXmI/AAAAAAAAAGQ/YKIk3CIUazc/s640/5.PNG" width="596" /></a></div><div class="separator" style="clear: both; text-align: center;"><br />
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</div><div class="separator" style="clear: both; text-align: left;"><strong><span style="font-size: large;">Answers :</span></strong> </div><div class="separator" style="clear: both; text-align: left;"><br />
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</div><div class="separator" style="clear: both; text-align: left;">1.    A)  An outside chance          b)   Go for it                      c)  Highway Overpass</div><div class="separator" style="clear: both; text-align: left;">2.    A)  Foreign Language           b)   Who’s in charge          c)  Neon Lights</div><div class="separator" style="clear: both; text-align: left;">3.    A)  I’m bigger than you         b)  Platinum                       c)  Break in Custom</div><div class="separator" style="clear: both; text-align: left;">4.   A) Ill in bed                           b)  Safety in Numbers        c)  Read between the lines</div><div class="separator" style="clear: both; text-align: left;">5.   A)  Tip-toe through the tulips b)  Alice in Wonderland     c) Merry go round</div><div class="separator" style="clear: both; text-align: left;"><br />
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Image puzzles with Answers - II

Image puzzles with Answers This puzzles are based on the images we need to find out the phrase. It shows the our identifi...

Infosys interview Puzzles with Answers

<div style="text-align: center;"><strong><span style="font-size: large;">Infosys interview puzzles with Answers</span></strong></div><div style="text-align: center;"><br />
</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Puzzle 1</strong> :  9 cards are there. u have to arrange them in a 3*3 matrix. cards are of 4 colors.they are red,yellow,blue,green. conditions for arrangement: one red card must be in first row or second row.2 green cards should be in 3rd column. Yellow cards must be in the 3 corners only. Two blue cards must be in the 2nd row. Atleast one green card in each row.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Answer :</strong> </div>                        Yello     Red        Green<br />
                         Blue     Blue        Green<br />
                         Yellow Green     Yellow<br />
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<div style="text-align: justify;"><strong>Puzzle 2 :</strong>   In a soap company a soap is manufactured with 11 parts. For making one soap you will get 1 part as scrap. At the end of the day u have 251 such scraps. From that how many soaps can be manufactured?</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Answer :</strong>  22 + 2+ 1 = 25.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Puzzle 3 :</strong> There are five thieves, each loot a bakery one after the other such that the first one takes 1/2 of the total no. of the breads plus 1/2 of a bread. Similarly 2nd, 3rd,4th and 5fth also did the same. After the fifth one no. of breads remained are 3. Initially how many breads were there?</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Answer :</strong>  31</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Puzzle 4 :</strong> Two candles of equal lengths and of different thickness are there. The thicker one will last of six hours. The thinner 2 hours less than the thicker one. Ramesh light the two candles at the same time. When he went to bed he saw the thicker one is twice the length of the thinner one. For how long did Ramesh lit two candles .</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Answer </strong>: 3 hours</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Puzzle 5</strong> : There are 5 persons who have won top 5 places in an event Olympics one of them asks all the 5 regarding their positions they reply as a: I am not the last b: c is in third place c: e is behind a d: b is in 1st place e: d is not the first find positions in order. </div><div style="text-align: justify;"><strong>Answer  </strong>:  bdcae</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Puzzle 6</strong> :  If one tyre of a car suddenly gets stolen…. and after sometime u find the tyre without the screws how will u make ur journey complete? </div><div style="text-align: justify;"><strong>Answer :</strong> Open 3 screws, 1 from each tyre and fix the tyre.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Puzzle 7</strong> : How will you recognize the magnet & magnetic material & non-magnetic material?</div><div style="text-align: justify;"><strong>Answer</strong> : Drag one piece of material over another. There is no attractive force in the middle portion of the magnet. OR Get a piece of thread and tie up with the one bar and check for poles. If it iron bar then it moves freely and if it is magnetic bar then it fix in one direction according to poles.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Puzzle 8</strong> : You are given a cake; one of its corner is broken. How will u cut the rest into Two equal parts?</div><div style="text-align: justify;"><strong>Answer </strong>:  Slice the cake</div><br />
<strong>Puzzle 9</strong> : What is the height of room if after entering the room with a watch ur head strikes a hanging bulb?<br />
<strong>Answer</strong>: Oscillate the hanging bulb. Calculate the time period for one complete oscillation by Simple Harmonic Motion (SHM) of the handing bulb. Put it in the<br />
formula T=2 * 3.14 * (L/G)^1/2<br />
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L will be the length of the hanging thread.<br />
Add the L with ur height to get the height of the room.<br />
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OR<br />
Drop it from the room and find the time at which it strikes the floor. Using physics formula s = (at^2)/2 (IM NOT SURE ABOUT THIS ONE)<br />
<strong>Puzzle 10 :</strong> Can u make 120 with 5 zeros?<br />
<strong>Answer :</strong>  Factorial (factorial (0)+factorial (0)+factorial (0)+factorial (0)+factorial (0)) = 120<br />
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<strong>Puzzle 11</strong> :  There are three people A, B, C. Liars are of same type and Truth speaking people are of same type. Find out who is speaking truth and who is speaking false from the following statements:<br />
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a) A says: B is a liar.<br />
b) B says: A and C are of same type.<br />
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<strong>Answer </strong>: lets assume A is speaking truth. It means B is a liar then it means A and C are not of same type.<br />
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<div style="text-align: justify;"><strong>Puzzle 12 :</strong> Ann, Boobie, Cathy and Dave are at their monthly business meeting.  Their occupations are author, biologist, chemist and doctor, but not  necessarily in that order.  Dave just told the biologist that Cathy was on her way with doughnuts.  Ann is sitting across from the doctor and next to the chemist. The  doctor was thinking that Boobie was a goofy name for parent's to choose,but didn't say anything. What is each person's occupation? </div><br />
<div style="text-align: justify;"><strong>Answer:</strong>  Since Dave spoke to the biologist and Ann sat next to the chemist and across the doctor, Cathy must be the author and Ann the biologist. The doctor didn't speak, but David did, so Bobbie is the doctor and Dave the chemist. </div>

Infosys interview Puzzles with Answers

Infosys interview puzzles with Answers Puzzle 1 : 9 cards are there. u have to arrange them in a 3*3 matrix. cards are of 4 colors.they ...

Paul Sloane's list of Classic Lateral Thinking Puzzles with Answers

<strong><span style="font-size: large;">The Puzzles</span></strong><br />
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<strong>Puzzle 1. The man in the Elevator</strong><br />
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<div style="text-align: justify;">A man lives on the tenth floor of a building. Every day he takes the elevator to go down to the ground floor to go to work or to go shopping. When he returns he takes the elevator to the seventh floor and walks up the stairs to reach his apartment on the tenth floor. He hates walking so why does he do it? </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">This is probably the best known and most celebrated of all lateral thinking puzzles. It is a true classic. Although there are many possible solutions which fit the initial conditions, only the canonical answer is truly satisfying.</div><br />
<strong>Answer </strong>: The man is (of course) a dwarf. Variants of this puzzle include the clue that on rainy days he goes up in the elevator to the tenth floor (he uses his umbrella!) <br />
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<strong>Puzzle 2. The Man in the Bar</strong><br />
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<div style="text-align: justify;">A man walks into a bar and asks the barman for a glass of water. The barman pulls out a gun and points it at the man. The man says 'Thank you' and walks out. </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">This puzzle has claims to be the best of the genre. It is simple in its statement, absolutely baffling and yet with a completely satisfying solution. Most people struggle very hard to solve this one yet they like the answer when they hear it or have the satisfaction of figuring it out. </div><div align="justify"><br />
</div><div align="justify"><strong>Answer :</strong> The man had hiccups. The barman recognized this from his speech and drew the gun in order to give him a shock. It worked and cured the hiccups - so the man no longer needed the water. </div><br />
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The is a simple puzzle to state but a difficult one to solve. It is a perfect example of a seemingly irrational and incongruous situation having a simple and complete explanation. Amazingly this classic puzzle seems to work in different cultures and languages. <br />
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<strong>Puzzle 3. The Man who Hanged Himself</strong><br />
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<div style="text-align: justify;">Not far from Madrid, there is a large wooden barn. The barn is completely empty except for a dead man hanging from the middle of the central rafter. The rope around his neck is ten feet long and his feet are three feet off the ground. The nearest wall is 20 feet away from the man. It is not possible to climb up the walls or along the rafters. The man hanged himself. How did he do it? </div><br />
<strong>Answer :</strong> He climbed on a block of ice which has since melted. <br />
This one is often stated with the clue of a puddle of water, but surely this is too much assistance. It is one of several problems which depend on the change of state of water (snow or ice to water or steam). <br />
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<strong>Puzzle 4. Death in a Field</strong><br />
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<div style="text-align: justify;">A man is lying dead in a field. Next to him there is an unopened package. There is no other creature in the field. How did he die? </div><br />
<div style="text-align: justify;"><strong>Answer :</strong>   The man had jumped from a plane but his parachute had failed to open. It is the unopened package. This is sometimes given with the following rather elegant clue - as he approached the centre of the field he knew he was going to die. This is another of the top classics which is right up there with 'The Man in the Bar'. If the solver is thinking along the wrong lines (i.e. in the two dimensions of the ground) then the lateral jump to the third dimension can be tough to make. </div><br />
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<strong>Puzzle 5. Anthony and Cleopatra</strong><br />
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<div style="text-align: justify;">Anthony and Cleopatra are lying dead on the floor of a villa in Egypt. Nearby is a broken bowl. There is no mark on either of their bodies and they were not poisoned. How did they die? </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Answer :</strong>  Anthony and Cleopatra were goldfish whose bowl was knocked over by a clumsy dog.  This is one of a set of puzzles which deceive by using human names for animals. This is not a very satisfactory basis for a good puzzle but despite that, the puzzle has enduring popularity. </div><br />
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<strong>Puzzle 6. The Coal, Carrot and Scarf</strong><br />
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Five pieces of coal, a carrot and a scarf are lying on the lawn. Nobody put them on the lawn but there is a perfectly logical reason why they should be there. What is it? <br />
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<strong>Answer :</strong> They were used by children who made a snowman. The snow has now melted.  Another change of state puzzle. After this you should be on the look-out for them! <br />
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<div style="text-align: justify;"><strong>Puzzle 7. Trouble with Sons</strong></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">A woman had two sons who were born on the same hour of the same day of the same year. But they were not twins. How could this be so? </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Answer :</strong> They were two of a set of triplets (or quadruplets etc.)  This simple little puzzle stumps many people. They try outlandish solutions involving test-tube babies or surrogate mothers. Why does the brain search for complex solutions when there is a much simpler one available? </div><div style="text-align: justify;"><br />
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</div><div style="text-align: justify;"><strong>Puzzle  8. Push that Car</strong></div><div style="text-align: justify;">A man pushed his car. He stopped when he reached a hotel at which point he knew he was bankrupt. Why? </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Answer : He was playing Monopoly. </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Puzzle 9. The Arm of the Postal Service</strong></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">One day a man received a parcel in the post. Carefully packed inside was a human arm. He examined it, repacked it and then sent it on to another man. The second man also carefully examined the arm before taking it to the woods and burying it. Why did they do this? </div><div style="text-align: justify;">This one probably has more variations than any other. A great one to puzzle out. It requires plenty of good questions. </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Answer :</strong> The three men had been stranded on a desert island. Desperate for food, they had agreed to amputate their left arms in order to eat them. They swore an oath that each would have his left arm cut off. One of them was a doctor and he cut the arms off his two companions. They were then rescued. But his oath was still binding so he later had to have his arm amputated and sent to his colleagues. </div><div style="text-align: justify;">This is often told with a further twist whereby a doctor pays a tramp a large sum in order to amputate the tramp's arm which the doctor then sends to another man who inspects it etc. This variation can make for a long night of questioning! </div><div style="text-align: justify;"><br />
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</div><div style="text-align: justify;"><strong>Puzzle 10. Heaven</strong></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">A man died and went to Heaven. There were thousands of other people there. They were all naked and all looked as they did at the age of 21. He looked around to see if there was anyone he recognised. He saw a couple and he knew immediately that they were Adam and Eve. How did he know? </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><strong>Answer :</strong> He recognized Adam and Eve as the only people without navels. Because they were not born of women, they had never had umbilical cords and therefore they never had navels.  This one seems perfectly logical but it can sometimes spark fierce theological arguments! </div>

Paul Sloane's list of Classic Lateral Thinking Puzzles with Answers

The Puzzles Puzzle 1. The man in the Elevator A man lives on the tenth floor of a building. Every day he takes the elevator to go down ...