You have to boil a single egg for exactly nine minutes.

All you have are two hourglasses, able to measure (in sand) seven and four minutes, respectively.

How quickly, using only these two hourglasses, can you boil an egg?

Well if 16 is the maximum you could always run the 7 minute once and the 4 minute twice and still end up with 15 minutes.

Posted by Dulanjana on 2002-07-11 04:33:35