Here’s one I cribbed from the Internet. It’s out there, so don’t search it out for the answer.
A group of four people has to cross a bridge. It is dark, and they have to light the path with a flashlight. No more than two people can cross the bridge simultaneously, and the group has only one flashlight. It takes different time for the people in the group to cross the bridge:
- Annie crosses the bridge in 1 minute.
- Bob crosses the bridge in 2 minutes.
- Volodia Mitlin crosses the bridge in 5 minutes.
- Dorothy crosses the bridge in 10 minutes.
How can the group cross the bridge in 17 minutes? Post your answer as a comment below.