The Jelly Bean Problem, told by Tim Urban of Wait But Why is a different way of describing the classic Monty Hall Problem. I think the Jelly Bean Problem is easier to understand for kids who’ve never seen Let’s Make a Deal.
He says, “Here’s some good news. The way we do the death penalty here is that you have a chance to get out of it. Here’s the deal: Two of the jelly beans on the stump are poisonous—you’ll die within 30 seconds of eating either one of them. But one of the jelly beans isn’t poisonous and won’t harm you at all. All three of the jelly beans are delicious. The situation works like this: You pick one of the jelly beans and eat it, and if you happen to pick the non-poisonous one, you’re free to go. Cool?”
“Cool,” you say. He tells you it’s time to choose a jelly bean.
You choose the green one.