In the puzzle Four people on a Bridge we met four people who needed to cross a bridge at night. In this puzzle, there are five people who must cross two sequential bridges at night. As in the original puzzle, there are some hindrances:

The bridges can only support two people crossing at a time.

Each person has a different speed in which they can cross: 10 minutes, 7 minutes, 5 minutes, 2 minutes, and 1 minute.

They have only two flashlights to share among them.

What is the shortest amount of time it will take for all five people to cross both bridges?

i guess 15 min.  send the 10 min and 7 min people first.  when the 7 min person crosses, send the 2 min.  when 2min is across send the one min.  at this point the 10 min person will be across so send the 5 min person across alone

Posted by coryann on 2005-07-01 06:52:17