Monty Hall has hidden a prize behind one of these doors.

Monty invites you to choose one of the doors but won't let you open it just yet.

Monty opens one of the other doors to reveal - a goat!

He then asks you if you would like to change your mind or to stick with the door you originally chose. It's time to make your mind up, which door are you going to open?

Bad luck! When you opened your chosen door it also revealed a goat.

Congratulations! When you opened your chosen door it revealed a fantastic prize that you are now free to take home.

Well, whether or not you won the prize did you make your decision by guesswork or
logical reasoning? The question is, if we allowed you to play this game repeatedly
what strategy *should* you adopt?

No, you should infact *always* switch doors. This problem has fooled many
mathematicians since it was first posed in an American magazine article and continues to
present a seemingly paradoxical answer!

The probability of your first choice door hiding the prize is 1/3 and this can't change. But, 2/3 of the time you'll be wrong with your first choice and, by revealing a goat, Monty is effectively telling you which door the prize is behind the remaining 2/3 of the time! So by switching doors, your chances of getting the prize go up to 2/3!