Two doors contain a goat and one door contains a prize. You have to guess which door contains the prize. When you click a door, it won't open, but another door with a goat will open, leaving you with two closed doors. You can choose to stick with your first choice by clicking the same door again, or you can switch to the other door. Which strategy is better?
https://en.wikipedia.org/wiki/Monty_Hall_problem
