Like clockwork, the bridgemaster emerges every 17 minutes to terrify those who attempt to cross the bridge. Four brave souls approach and want to cross before the bridgemaster appears. Each one travels at their own pace; 1 minute, 2 minutes, 5 minutes, and 10 minutes respectively. Additionally, they have one torch between them and cannot cross the bridge without it.
The bridge cannot sustain more than two brave souls at a time. What is the order in which they should cross?
The first two brave souls cross first for a total of 2 minutes. The first brave soul brings back the Torch and thus 3 minutes have gone by. The last two cross for a total of 13 minutes upon which the second brave soul returns with the Torch for a total of 15 minutes. Finally the first two souls re-cross and 17 minutes have gone by. Quickly now, the bridgemaster is returning!