b r a y d e n . o r g / Random

This Web

All Webs

brayden.org

Books RSS

Random RSS

Software RSS

Other

There are 4 men who want to cross a bridge. They all begin on the same side. You have 17 minutes to get all of them across to the other side. 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. Each man walks at a different speed. A pair must walk together at the rate of the slower man's pace.

• Man 1: 1 minute to cross
• Man 2: 2 minutes to cross
• Man 3: 5 minutes to cross
• Man 4: 10 minutes to cross

For example if Man 1 and Man 4 walk across first, 10 Minutes have elapsed when they get to the other side of the bridge. If Man 4 returns with the flashlight, a total of 20 minutes have passed, and you have failed the mission.

Solution

<- - - 1,2
- - -> 1
<- - - 5,10
- - -> 2
<- - - 1,2

-- DaleBrayden - 31 Oct 2001