Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/5/84; site mtuni.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!whuxl!whuxlm!akgua!akguc!mtunh!mtuni!chip
From: chip@mtuni.UUCP (Charles Maurer)
Newsgroups: net.puzzle
Subject: Re: another puzzle
Message-ID: <241@mtuni.UUCP>
Date: Tue, 11-Feb-86 09:02:06 EST
Article-I.D.: mtuni.241
Posted: Tue Feb 11 09:02:06 1986
Date-Received: Thu, 13-Feb-86 01:05:48 EST
References: <1645@hound.UUCP>
Organization: AT&T ISL Holmdel NJ USA
Lines: 38

> 
> 
>      Three men are in a room. The room has no mirrors and the three men
> are in a straight line such that the person in the back of the line
> can see the two people in front of him, the middle person can see
> only the person in front of him, and the person in front can't see
> anyone. Another person walks in with a bag containing 3 black hats
> and two red hats. The man pulls three hats at random out of the bag
> and places them randomly on the three men. He walks out of the room.
> The man in the back says,"I don't know what color hat I'm wearing."

For the man in back to know for sure what color hat he was
wearing, the two men in front of him would both have to be
wearing red hats.  This would mean he would have a black hat
on his own head.  Since he can't determine his hat color, at
least 1 of the men, if not both, in front of him must have
a black hat.

> The man in the middle says,"I don't know what color hat I'm wearing, either."

The man in front of him, upon hearing the response from the
man behind him would realize that either himself or the man 
in front of him HAS to be wearing a black hat, with the other 
hat being red or black.   If the man in front was wearing a red 
hat, then the middle man would know for sure that he was wearing 
a black hat.  If the man in front was wearing a black hat, then 
the middle man could be wearing either a black or a red hat, 
so the man in front must be wearing a black hat.

> Now tell me what color hat the man in the front of the line is wearing
> and why.
> 
> 
>                             *** GOOD LUCK ***
> 
> 
>                                                 Barry Friedman
>                                                 ihnp4!houxm!hound!5125kaf