The Monty Hall Problem
Pick a door!
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 other 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 take the switch?
That is the way the “Monty Hall Problem” is usually stated. Marilyn vos Savant published the problem with essentially this wording in 1990. In the recent film “21″ the problem appears in this form. Unfortunately, when stated this way, there is no indication in the problem whether the the host always must open a door with a goat or not. That condition is crucial. Read more