The Bridge and Torch Problem
Main Concept
A group of four friends is stranded on an island which is connected to the mainland by a single bridge. The bridge is very unstable and can only support, at most, two people at a time. It is nighttime and the four friends only have one torch, which must be used when crossing the bridge. It takes Harry one minute to cross the bridge, Lily two minutes, Victor five minutes, and Cindy eight minutes. Two people crossing the bridge together must move at the pace of the slower person because they must share the torch. Is it possible for the group to cross the bridge in 15 minutes?
Click the portrait of a person to select them to cross. You can select at most two people. To choose somebody else, you must unselect someone already selected by clicking their portrait again. Then, click "Cross" to make the selected person or pair cross. You can only cross from the side that has the torch.
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