Techfest 2008 Puzzles #1

Check out these puzzles posted on the IIT Bombay Techfest 2008 Website ! Just check’em out !!
The solution is posted the next post .


Can you work out what the letters represent and crack the code to reveal the hidden phrase or saying?

dx ia dfa iapd bxe fhka dx iahd dfa iapd


Five sailors survive a shipwreck and swim to a tiny island where there is nothing but a coconut tree and a monkey. The sailors gather all the coconuts and put them in a big pile under the tree. Exhausted, they agree to go to wait until the next morning to divide up the coconuts.

At one o’clock in the morning, the first sailor wakes up. He realizes that he can’t trust the others, and decides to take his share now. He divides the coconuts into five equal piles, but there is one coconut left over. He gives that coconut to the monkey, hides his coconuts (one of the five piles), and puts the rest of the coconuts (the other four piles) back under the tree.

At two o’clock, the second sailor wakes up. Not realizing that the first sailor has already taken his share, he too divides the coconuts up into five piles, leaving one coconut over which he gives to the monkey. He then hides his share (one of the five piles), and puts the remainder (the other four piles) back under the tree. At three, four, and five o’clock in the morning, the third, fourth, and fifth sailors each wake up and carry out the same actions. In the morning, all the sailors wake up, and try to look innocent. No one makes a remark about the diminished pile of coconuts, and no one decides to be honest and admit that they’ve already taken their share. Instead, they divide the pile up into five piles, for the sixth time, and find that there is yet again one coconut left over, which they give to the monkey.

The Question: What is the smallest amount of coconuts that there could have been in the original pile?


A computer scientist has two sons named Chip and Hal. After the father’s death, as specified in his will, the executor of the estate assigns two positive integers to the sons – one to Chip and one to Hal. Neither son knows the other’s number. Chip and Hal are then told that the two integers could possibly be equal and that the product of the two integers is either 8 or 16. The sons are also informed that the first one to determine his brother’s number will inherit their father’s entire estate. Immediately thereafter, the following conversation transpires between the two brothers.

Chip: I have no idea what your number is.

Hal: Same here.

Chip: You’ll have to give me a hint.

Hal: Same here.

Determine Hal’s number.


  1. There are five houses.

  2. The PUNJABI lives in the red house.

  3. The RAJASTHANI owns the dog.

  4. Coffee is drunk in the green house.

  5. The MARATHI GUY drinks tea.

  6. The green house is immediately to the right of the ivory house.

  7. The Old Gold smoker owns snails.

  8. Kools are smoked in the yellow house.

  9. Milk is drunk in the middle house.

  10. The TAMIL GUY lives in the first house.

  11. The man who smokes BEEDI lives in the house next to the man with the fox.

  12. Kools are smoked in the house next to the house where the horse is kept.

  13. The Lucky Strike smoker drinks orange juice.

  14. The BIHARI smokes Parliaments.

  15. The TAMIL GUY lives next to the blue house.

Now, who drinks water? Who owns the DONKEY?

In the interest of clarity, it must be added that each of the five houses is painted a different color, and their inhabitants are of different national extractions, own different pets, drink different beverages and smoke different brands of local cigarettes. One other thing: In statement 6, right means your right.


Each letter a, b, c, d, e, f in the following multiplication problems denotes a unique nonzero integer from 1 to 9. Thus any permutation of these letters forms a distinct six-digit number. Determine the six-digit number abcdef, where

fabcde = 5•abcdef
efabcd = 4•abcdef
defabc = 6•abcdef
cdefab = 2•abcdef
bcdefa = 3•abcdef.


Techfest Puzzles Solution #1


These are the answers to the puzzles posted in the online puzzle series on the official website of Techfest 2008,IIT Bombay


dx ia dfa iapd bxe fhka dx iahd dfa iapd

to be the best you have to beat the best


Answer: 56

Every sailor leaves 4/5(n-1) coconuts of a pile of n coconuts. This results in an awful formula for the complete process (because every time one coconut must be taken away to make the pile divisible by 5): 4/5(4/5(4/5(4/5(4/5(4/5(p-1)-1)-1)-1)-1)-1), where p is the number of coconuts in the original pile, must be a whole number. The trick is to make the number of coconuts in the pile divisible by 5, by adding 4 coconuts. This is possible because you can take away those 4 coconuts again after taking away one fifth part of the pile: normally, 4/5(n-1) coconuts are left of a pile of n coconuts; now 4/5(n+4)=4/5(n-1)+4 coconuts are left of a pile of n+4 coconuts. And because of this, the number of coconuts in the pile stays divisible by 5 during the whole process. So we are now looking for a p for which the following holds: 4/5×4/5×4/5×4/5×4/5×4/5×(p+4)=(46/56)×(p+4), where p is the number of coconuts in the original pile, must be a whole number. The smallest (p+4) for which the above holds, is 56. So there were p=56-4=15621 coconuts in the original pile.


This is an easy question

The correct answer is 4.



    try to google for zebra puzzle


2. abcdef = 142857. Note that a = 1 immediately from the first equation. Incidentally, 142857 is the only number known to have this cyclic property.