CAN THEY MAKE IT ALIVE???
Four men can cross a bridge in 1, 2, 5, and 10 minutes respectively. It is late at night and they have one flashlight between them. We know that:
1. At most only two men can cross at a time (they
must go at the slower man's rate).
2. They need the flashlight to cross the bridge.
3. The bridge will blow up in 17 minutes.
Can all four men make it across the bridge alive? Explain why or why not?
The answer is no.
A= 1 min B= 2 min C= 5 min D= 10 min
First A and D must go first ( 10 min )
A then have to run back with the tourch light (1 min) (6 min left)
Why? A and D must go together first ( 10 min )
A has to run back ( 1 min ) ( 6 min left )
3 people are at the start ( 1, 2, 5 min ) ( at any combination the least is 7 min )
Thus there is no possible answer.