Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10 5/3/83; site houxz.UUCP
Path: utzoo!linus!decvax!harpo!floyd!clyde!ihnp4!houxm!houxz!halle1
From: halle1@houxz.UUCP (J.HALLE)
Newsgroups: net.math
Subject: Re: Let's Make a Deal
Message-ID: <543@houxz.UUCP>
Date: Wed, 12-Oct-83 14:06:32 EDT
Article-I.D.: houxz.543
Posted: Wed Oct 12 14:06:32 1983
Date-Received: Thu, 13-Oct-83 21:46:13 EDT
References: <169@mi-cec.UUCP>, <165@kobold.UUCP>
Organization: Bell Labs, Holmdel NJ
Lines: 6

This is very similar to the coin&chest problem of earlier in the year.
It also is a Restricted Choice problem.  Assume you pick door one.
Now, if you are wrong, Monty's choice is restricted; he must show you
the one he does.  If you are right, his choice is random.  Thus the
fact that he showed you a particular door implies that he had to, making
the switch proper.