There are 4 people who want to cross a bridge and all begin on the same side. You
have 17 minutes to get all of them across to the other side. It is night and there is
just one ashlight. A maximum of two people can cross at one time. Any party who
crosses, either 1 or 2 people, must have the ashlight with them. The ashlight must
be walked back and forth, it cannot be thrown across or otherwise transferred to the
other side. Each person walks at a different speed. A pair must walk together at the
rate of the slower person's pace.
Person 1: 1 minute to cross
Person 2: 2 minutes to cross

Question

There are 4 people who want to cross a bridge and all begin on the same side. You
have 17 minutes to get all of them across to the other side. It is night and there is
just one ashlight. A maximum of two people can cross at one time. Any party who
crosses, either 1 or 2 people, must have the ashlight with them. The ashlight must
be walked back and forth, it cannot be thrown across or otherwise transferred to the
other side. Each person walks at a different speed. A pair must walk together at the
rate of the slower person's pace.
Person 1: 1 minute to cross 
Person 2: 2 minutes to cross

anonymous · Answer

Person 3: 5 minutes to cross Person 4: 10 minutes to cross
How do you get everyone across the bridge to the other side in 17 minutes or less?