The Monty Hall problem. Behind one of these doors is an amazing prize. Behind the other two are goats (which could be an amazing prize if you love goats). Choose a door and Monty will show you a door with a goat behind it. You can then decide to keep the door you've chosen by clicking it again, or you can switch by clicking the other door. The goats and prize move randomly with each new play of the game. The prize changes randomly as well. There is a right answer in terms of whether, statistically, you should switch or stay. Google "The Monty Hall Problem."
