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URL:  https://boards.fool.com/i-think-its-50-50-for-monte-hall-how-does-the-30398385.aspx

Subject:  Re: 5 Statistics Problems To Change Your View Date:  11/25/2012  3:15 PM
Author:  SuisseBear Number:  409552 of 567852

I think it's 50-50 for Monte Hall. How does the door know if this is "the same game" or a new one with only two doors to chose from? Monte may know, but he's not doing the choosing. Door=roulette wheel. No institutional memory. Every spin is independent of whatever came before.

Nope. The key is that the host knows, opens a booby prize door after you pick, and thereby gives you information that you didn't have upon your initial choice. If your initial choice was wrong (2/3 probability) then switching will ensure you win at 100%.
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