Bridge Puzzle*
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I have a math puzzle that I just can't get.

You have 4 people (A, B, C and D) that need to cross a bridge under 13 min and only 1 flashlight. You can only go with the flashlight, no more than 2 persons at a time, and always as fast as the slowest person. To cross the bridge persons need:
A=1min; B=2min; C=5min; D=6min.
How do you get all 4 of the across in only 13 min?

P.S. they can't go on each others back!
A.

* This puzzle is one of several well-known puzzles of this type. In fact, it's a clever version of traditional crossing river puzzles.

 Mini-Contest 5 - Bridge Puzzle is FINISHED

 It was our fifth mini-contest. Because of some technical problem now we have the first six+one correct answers and propose this contest's results and some details about the puzzle and its solution. With this Mini-Contest 5 is finished.

 Contest Results

 The winners are: 1. Jensen Lai. 2. Hüsnü Sincar. 3. Nicole Takahashi. 4. Tanya Bulls. 5. Nigel Wilson. 6. Terry & Lisa. 7. Alex Packard.

 Posted: January 24, 2002  |  Last Updated: July 8, 2007