> There are no tricks, this is a straight forward problem. Allegedly, this is one of the questions for potential Microsoft employees. I must warn you, you can really get caught up trying to solve this problem. One guy solved it by writing a Computer program, although that took him 37 minutes to develop (compiled and ran on the 1st try though). Another guy solved it in three minutes. A group of 50, at Motorola, couldn?t figure it out at all.
>
> See how long it takes you.
>
> Here we go...
>
> "U2" has a concert that starts in 17 minutes and they must all cross a bridge to get there. All 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 band member walks at a different speed. A pair must walk together at the rate of the slower man's pace:
>
> Bono: - 1 minute to cross
> Edge: - 2 minutes to cross
> Adam: - 5 minutes to cross
> Larry: - 1 0 minutes to cross



Bono and edge go 2 min
bono comes back 3 min
adam and larry go 13 min
edge comes back 15 min
bono and edge go 17 min

1 minutes 13 seconds to figure it out



>
> For example: if Bono and Larry walk across first, 10 minutes have elapsed when they get to the other side of the bridge. If Larry then returns with the flashlight, a total of 20 minutes have passed and you have failed the mission.
>
> 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.
>
> Note: Microsoft expects you to answer this question in under 5 minutes!