The Monty Hall problem is a brain teaser, based on the television game show, Let's Make a Deal hosted by Monty Hall.
The teaser goes like this:
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? -ref:
Use the following simulator to test your own assumptions about the answer to this problem.