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?

7 and 4 = 4
3 and 4 = 3
7 and 1 = 1
1 = 1

= 9

Posted by Cheradenine on 2002-07-05 07:18:06