Microsoft Puzzle:
(supposedly asked by Microsoft during interviews)
MBD has a concert that starts in 17 minutes and four people must all cross a bridge to get there. All four men begin on the same side of the bridge. You must help them across to the other side. It is night. There is one flashlight. A maximum of two people can cross at one time. Any party who crosses, either 1 or 2 people, must have the flashlight with them.
The flashlight must be walked back and forth, it cannot be thrown, etc.
Each person walks at a different speed. A pair must walk together at the rate of the slower man’s pace:
* Chaim: – 1 minute to cross
* Yankel: – 2 minutes to cross
* Ruven: – 5 minutes to cross
* Shimon: – 10 minutes to cross
Notes: There is no trick behind this. It is the simple movement of resources in the appropriate order. There are two known answers to this problem. This is based on a question that Microsoft gives to all prospective employees.
Source: http://puzzleszone.blogspot.com/2008/08/microsoft-puzzle.html