Interview Puzzles

Stack of 'must-know' interview puzzles !

Lost soldier

A soldier looses his way in a thick jungle. At random he walks from his camp but mathematically in an interesting fashion.First he walks one mile East then half mile to North. Then 1/4 mile to West, then1/8 mile to South and so on making a loop.Finally how far he is from his camp and in which direction?

A bad king and neighbouring wife

A bad king has a cellar of 1000 bottles of delightful and very expensive wine. A neighbouring queen plots to kill the bad king and sends a servant to poison the wine. (un)fortunately the bad king?s guards catch the servant after he has only poisoned one bottle. Alas, the guards don?t know which bottle but know that the poison is so strong that even if diluted 1,000,000 times it would still kill the king. furthermore, it takes one month to have an effect. The bad king decides he will get some of the prisoners in his vast dungeons to drink the wine. Being a clever bad king he knows he needs to murder no more than 10 prisoners - believing he can fob off such a low death rate - and will still be able to drink the rest of the wine at his anniversary party in 5 weeks time. explain how?.

Palindrome of dates

This year on October 2, 2001, the date in MMDDYYYY format will be a palindrome (same forwards as backwards). 10/02/2001 when was the last date that this occurred on? (see if you can do it in your head!)

Calculate fare

Mr. Subramaniam rents a private car for Andheri-Colaba-Andheri trip. It costs him Rs. 300 everyday.One day the car driver informed Mr. Subramaniam that there were two studentsfrom Bandra who wished to go from Bandra to Colaba and back to Bandra. Bandra is halfway between Andheri and Colaba. Mr. Subramaniam asked the driver to let the students travel with him.On the first day when they came, Mr. Subramaniam said, "If you tell me the mathematically correct price you should pay individually for your portion of the trip, I will let you travel for free."How much should the individual student pay for their journey?

Truth or lie?

When Alexander the Great attacked the forces of Porus, an Indian soldier was captured by the Greeks. He had displayed such bravery in battle, however,that the enemy offered to let him choose how he wanted to be killed. They told him, "If you tell a lie, you will put to the sword, and if you tell the truth you will behanged."The soldier could make only one statement. He made that statement and wen tfree. What did he say?

Who is taller?

500 men are arranged in an array of 10 rows and 50 columns according to their heights.Tallest among each row of all are asked to come out. And the shortest among them is A.Similarly after resuming them to their original positions, the shortest among each column are asked to come out. And the tallest among them is B.Now who is taller A or B ?

Candle problem

Sam was studying for his examinations and the lights went off. It was around 1:00 AM. He lighted two uniform candles of equal length but one thicker than the other. The thick candle is supposed to last six hours and the thin one two hours less. When he finally went to sleep, the thick candle was twice as long as the thin one.For how long did Sam study in candle light?

Count 0s

A certain street has 1000 buildings. A sign-maker is contracted to number the houses from 1 to 1000. How many zeroes will he need?

Sand clock problem

You have to sand clocks, 1 to measure 4 minutes and the other to measure 7 minutes. How would you measure 9 minutes in exactly 9 minutes?

100 doors

You have 100 doors in a row that are all initially closed. you make 100 passes by the doors starting with the first door every time. the first time through you visit every door and toggle the door (if the door is closed, you open it, if its open, you close it). the second time you only visit every 2nd door (door #2, #4, #6). the third time, every 3rd door (door #3, #6, #9), etc, until you only visit the 100th door. question: what state are the doors in after the last pass? which are open which are closed?

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