There are four Scouts who want to cross a bridge at night, by the light of a flashlight that one of them has. They all begin on the same side and the bridge can only hold two of them at once. They all walk different speeds and take different amounts of time to cross the bridge, namely: 1,2,5 and 10 minutes.
Whenever two of them are on the bridge together they must walk at the pace of the slower person. Any party who crosses the bridge must carry the flashlight, and the flashlight must be walked back to the other side to bring over any remaining people. The flashlight cannot be thrown etc.
For example if the 1 minute Scout and the 10 minute Scout walk across, 10 minutes have elapsed when the get to the far side. If the 1 minute Scout then crosses back with the flashlight, a total of 11 minutes have elapsed, and there are still three people on the wrong side of the bridge!
Describe how they all cross in 17 minutes.
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