Suppose you're on a game show...

...and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?

Answer: Yes, there is an advantage.

Q: Why?

Don't Google this because it's no fun that way.

If you're thinking it's 50/50 at the end you're incorrect. If you give up and can't prove it's not look up 'Monty Hall problem'.