Adam, Edge, Bono and Larry need to cross this bridge. The bridge is only strong enough to hold 2 people at a time. It's a dark moonless night, and the bridge has many treacherous holes, so a pair (or a single person) can only cross if they carry a flashlight. The group only has 1 flashlight.
The bridge will collapse in 17 minutes. Adam is really fast and can cross the bridge in 1 minute. Edge can do it in 2. Bono takes 5 minutes. Larry is the slowest of all, and it takes him 10 minutes to cross.
How can all 4 of them get across before the bridge collapses?