Here's a very old one you may or may not have heard. It's called "The Puzzle of the Jealous Husbands." The only change I made was to give the characters names -- the structure of the puzzle, as well as the solution, is unchanged.
Adam and his wife Betty, Charles and his wife Diane, and Emilio and his wife Felicity (note: I purposely chose these names in alphabetical order, to make it easier to know who's who) are all traveling together, when they come to a river. The good news is that there is a boat available which can hold a maximum of 2 people. Unfortunately, Adam, Charles, and Emilio don't completely trust each other. In fact, none of the men are willing to have their wives be in the presence of any of the other men unless the husband is also present. For example, Emilio won't leave Felicity in Adam's and/or Charles' company unless he's there. Under these constraints, find a way for all of them to cross the river. Note that the boat is the only way across, and the jealousy constraint applies to being on the same side of the river and to being in the boat. Note also that nobody has a problem with two (or all three) women being together without any husbands. My one hint to you is that the shortest possible solution involves 11 separate crossings of the river.
