[zheshishei]

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

[throwmeout]

http://en.wikipedia.org/wiki/Bridge_and_torch_problem