A game-show host has placed a car behind one of three doors There is a goat behind each of the other doors First you point toward a door he says Then I'll open one of the other doors to reveal?

the answer is switch because when you first pick you have a 1/3 chance of getting the car and a 2/3 chance of picking a goat, when the host opens up one of the other doors with a goat there is now a 2/3 chance that the car is in the other door you did not pick. if you run through the possibilities you will see: lets say you always pick door number one so 1. goat 2 car 3 goat ....... 1 car 2 goat 3 goat .... 1 goat 2 goat 3 car... you can see that twice out of three times you will get the car by switching