[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference rusure::math

Title:Mathematics at DEC
Moderator:RUSURE::EDP
Created:Mon Feb 03 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2083
Total number of notes:14613

825.0. "To tell the truth?" by STAR::HEERMANCE (Martin, Bugs 5 - Martin 0) Mon Feb 08 1988 14:07

    Here's a classic logic problem in a slightly altered form.
    
    There is a city where everyone who lives in the west side always
    tells the truth.  While everyone who lives in the east side will
    always lie.

    During the day the citizens move freely throughout the city.  In
    the evening they return to their homes.  You are a stranger, and
    you're lost during the day.  What one question can you ask which
    will tell you which side of the city you're in.

   Enjoy,
   Martin H.
T.RTitleUserPersonal
Name
DateLines
825.1East side, west side ...STARZ::LOHMILLERMon Feb 08 1988 17:315
    Do you live in this side of the city?
    
    If the answer is "yes" then you're in the west side. If it's "no"
    then your in the east side.
                                                                  
825.2let see now ...CSDPIE::KOSTASHe is great who confers the most benefits.Mon Feb 08 1988 17:3738
    Well,
    
        one question you can ask is this:
    
     Hello, my name is Kostas, can you tell me from which way did the
    sun come up this morning?
    
    If the answer is: 
         From the West side 
            then you are talking to lier
                 who also lives in the East side of the city. 
                 let truth_indicater = -1
    If the answer is:
         From the East side 
            then you are talking to someone who tells the truth
                 who also lives in the West side of the city. 
                 let truth_indicater = 1

    Now you can ask: Which side of the city am I now?

    If the answer you get is West and truth_indicater is equal to -1
	    then you are in the East side
    esle if the answer you get is West and truth_indicater is equal to 1
	    then you are in the West side

    If the answer you get is East and truth_indicater is equal to -1
	    then you are in the West side
    else if the answer you get is East and truth_indicater is equal to 1
	    then you are in the East side
    

    /Enjoy,
    
    Kostas
    

    BTW If I told you I was lying and I did not lie, did I say the truth?
    
825.3Playing by the rules,8BALL::HALLYBYou have the right to remain silent.Mon Feb 08 1988 20:404
    "If you lived on the opposite side of the city where you actually
    live, what side of the city would you say we were in now?"
    
    Answer is opposite of what you are told.
825.4Do you live here?STAR::HEERMANCEMartin, Bugs 5 - Martin 0Tue Feb 09 1988 12:4316
    RE: .1
    
    A gold star for you, thats the answer I was thinking of.
    
    RE: .2
    
    A bit complicated but your logic was fine.  I like your BTW it
    was a nice touch.
    
    
    Re: .3
    
    I like your answer better than my own.  It's more like the answer
    to a similar puzzle involving a liar and a truth teller.
    
    Martin H.