Four people need to cross a bridge at night. They have one flashlight for the four of them, but the bridge is only wide enough for two to cross at a time. Because it's so dark, anyone crissing the bridge must do so with the flashlight.

Person A can walk across in 1 minute. Person B takes 2 minutes; person C -- 5 minutes, and finally person D needs a full 10 minutes to cross. Naturally, if two people are crossing the bridge, they move with the speed of the slower person.

What is the shortest amount of time it will take for all four to get to the other side?

it's kinda easy... i'm not positive though. i just think that if 2 people cross it then the first person should go back 2 the other 2 and hand the flash light 2 the 3rd person. then the 3rd and 4th person will walk across and the 4th person will comeback with the flash light and take the 1st person with them. u n'ah mean? that won't take a long time. it'll b pretty simple.

Posted by omar on 2004-02-21 15:37:57