It'll take 17 minutes for all the people to cross if they all start on the same side: start: 1,2,7,10| 1: 7,10|1,2 = 2 minutes 2: 1,7,10|2 =

It'll take 17 minutes for all the people to cross if they all start on the same side: start: 1,2,7,10| 1: 7,10|1,2 = 2 minutes 2: 1,7,10|2 = 1 minute 3: 1|2,7,10 = 10 minutes 4: 1,2|7,10 = 2 minutes 5: |1,2,7,10 = 2 minutes total: 17 minutes