Riddle: There are four people trying to cross a bridge. They each take a different amount of time to cross: 1 minute ; 2 minutes ; 5 minutes ; and 10 minutes. The bridge can only hold 2 people at a time, so they must cross the bridge in pairs. The two people paired together must travel at the speed of the slower person (i.e. 5 min. & 10 min. person paired takes 10 min. total to go across). After two people have crossed, one person must return to the other side to give the â€˜all clear.â€™ (i.e. the 5 min. person would return, taking 5 min, and bringing the total time to 15). Get all four people across in 17 min.