Lighter: The Wikipedia article is long mainly because it demonstrates multiple methods of solving the problem, showing that they all come to the same conclusion. You don't have to understand all of them. Pick one.

It also gives the history of the problem and considers some psychological reasons why some people come to the wrong conclusion.

It's not the only problem that confuses people. Have you ever heard of the Mythbusters airplane takeoff problem? I'll bet they're still arguing about that on the Mythbusters forum. But if people want to discuss that here, I think somebody should start a new thread.