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Path: utzoo!linus!decvax!harpo!eagle!mhuxi!houxm!ihnp4!we13!we53!kcwin!thh
From: thh@kcwin.UUCP
Newsgroups: net.math
Subject: Let's Make a Deal
Message-ID: <113@kcwin.UUCP>
Date: Thu, 13-Oct-83 15:30:11 EDT
Article-I.D.: kcwin.113
Posted: Thu Oct 13 15:30:11 1983
Date-Received: Fri, 14-Oct-83 21:48:53 EDT
Lines: 16


I think I've come up with a simple explanation of why it pays to switch:

First let's assume that I always switch.
If I choose the correct door (probability 1/3) and then switch I will
always end up with the wrong door (no matter which door Monty shows me.)

However, if I choose the wrong door (probability 2/3) and then switch
I will always end up with the door with the grand prize (because Monty
will have exposed the door without it).

So I'll win 2/3 of the time if I always switch.  If I never switch
then my chances of winning will never change from the original 1/3.

			Tom Hadley, Western Electric, Kansas City
			we53!kcwin!thh