Please help this familiy to cross to the other side of the bridge. Notice that: It is night. There is only ONE lamp. A maximum of 2 persons can cross at one time, and they must have the lamp with them. Each person walks at a different speed: 1 sec, 3 sec, 6 sec, 8 sec and 12 sec. A pair must walk together at the rate of the slower person. The lamp enough for 30 sec only!!