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?
Well I will pass C and D fists (there goes 10 min) then at the
end, point the flashlight back so the others one can see, and then A
and B came together, there you have 12 min.
Any way if they have to go back It's another story about 17 min.
Edited on July 8, 2004, 10:47 am
without to much cheking...
