The Monty hall problem is (from wiki)
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?
So the answer is supposed to be switching doors as that gives you 2/3 chance opposed to not switching which only gives you a 1/3 chance, but I can’t seem to wrap my head around Why?