"U2" has a concert that starts in 17 minutes and they 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 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 : 10 minutes to cross
Bono : 1 minute to cross
Edge : 2 minutes to cross
Adam : 5 minutes to cross
Larry : 10 minutes to cross