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?

Could we edit the link in the problem text?  As is, the link goes directly to a comment on "Four people on a bridge" in which the solution is displayed.  I'd hate to see the old classic spoiled if anyone accidently looked.  It would be better if it linked to the problem itself, not a comment.

Posted by Tristan on 2005-06-25 23:00:12