Saturday, August 20, 2005

Game Show

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 number 1, and the host, who knows what's behind the doors, opens another door, say number 3, which has a goat. He says to you, "Do you want to pick door number 2?" Is it to your advantage to switch your choice of doors?


  1. yeah it is to your advantage because you aren't really losing anything by picking another door. i mean you are either going to get another goat (wjich you had in the first place) or you could end up with a car.

  2. Good answer. But I was thinking of not just losing out, but gaining!

  3. This question was asked by Craig Whitaker in the "Ask Marilyn" in Parade Magazine in 1996. Marilyn's answer got quite a backlash, but it turns out she got it right.
    If you switch to the other door, instead of having a 1 in 3 chance of winning, you'll have a 2 in 3 chance! The idea is simple but quite counterintuitive. By making a "blind" choice between the three doors, you have a 1 in 3 chance of being right, but a 2 in 3 chance of being wrong. Then door 3 is removed. By switching away from your first choice to door 2, you'll now have a 2 in 3 chance of being right!

  4. If you'd like to try out this answer in an interactive way, use cards instead of doors. Always switch away from your first choice. If you keep track of how many times you get the "prize", you'll see soon enough that Marilyn got it right!

    You might also try searching on the web for the "Monty Hall" problem.


Leave your answer or, if you want to post a question of your own, send me an e-mail. Look in the about section to find my e-mail address. If it's new, I'll post it soon.

Please don't leave spam or 'Awesome blog, come visit mine' messages. I'll delete them soon after.

Enter your Email and join hundreds of others who get their Question of the Day sent right to their mailbox

Preview | Powered by FeedBlitz

The Lamplight Manor Puzz 3-D
Are you looking for a particular puzzle, riddle, question, etc? Or do you want to find the answer today rather than wait till tomorrow!