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?

1 min and 2 min go so it's 2 min total, then 1 min come back so it's 3 min, 1 min and 5 min then go so it's 3+5=8 mins total.    1 min goes back (+1min) and picks up 7 mins so it's 7+1+1+8=17 mins total. then 1 min go back(+1 min) and picks up 10 mins(11 mins) ... and it's over ... total is ...

17+11=28 mins ... this is the fastest way if you take ...

10 and 7 go(17) and 7 comes backIt's already 24 mins so nice try ... ...

Edited on June 26, 2005, 1:17 am

Posted by j441167 on 2005-06-26 01:15:31