This question appeared in Edexcel maths paper, the students who took the exam vented their frustration on twitter.



The Monty Hall problem is a brain teaser, in the form of a probability puzzle, based on an American television game show. The problem was originally posed in a letter to the American Statistician in 1975. It became famous as a question from a reader's letter quoted in Marilyn vos Savant's "Ask Marilyn" column in Parade magazine in 1990.

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?

















