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. They must all get across to the other side within 17 mins. 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. The bridge is too long for the flashlight to be held at one end to shine the way, when crossing the bridge the light must be carried all the way.
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
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 themission.