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Math Help - Logic puzzle - Need some help

  1. #1
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    Logic puzzle - Need some help

    Not sure how to lay the out the truth table for the puzzle in order to solve it ( not sure which connectives to use in other words )

    Puzzle:

    In a certain country, every inhabitant is either a truth teller who always tells the truth, or a liar who always lies.
    While travelling in this country, you meet two people, Tom and Mark.
    Tom says, "Mark and I are both liars." is Tom a truth teller or a liar? What about Mark?

    Im guessing implications and conjunction come into play? could someone show me how it is done, need to do allot of these it seems ;<
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    Re: Logic puzzle - Need some help

    Quote Originally Posted by John540 View Post
    Puzzle:

    In a certain country, every inhabitant is either a truth teller who always tells the truth, or a liar who always lies.
    While travelling in this country, you meet two people, Tom and Mark.
    Tom says, "Mark and I are both liars." is Tom a truth teller or a liar? What about Mark?
    If Tom were a truth teller is it possible for "Mark and I are both liars." to be true?
    If it is false, what about Mark?
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  3. #3
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    Re: Logic puzzle - Need some help

    Could that mean that Tom is a liar and Mark is a truth teller? Err I am confused
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    Re: Logic puzzle - Need some help

    Quote Originally Posted by John540 View Post
    Could that mean that Tom is a liar and Mark is a truth teller? Err I am confused
    Why do you say that?

    Can you find any other combination that works? There are only three others.
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    Re: Logic puzzle - Need some help

    Tom is a liar Mark is a truth teller / Mark is a liar Tom is a truth teller / Both are lying / Both are truth tellers - What do I need to apply to this in order to solve it?
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    Re: Logic puzzle - Need some help

    Quote Originally Posted by John540 View Post
    Tom is a liar Mark is a truth teller / Mark is a liar Tom is a truth teller / Both are lying / Both are truth tellers - What do I need to apply to this in order to solve it?
    You use each of those four and see which is the only one makes the original statement (Tom says, "Mark and I are both liars.") work.
    Last edited by Plato; October 27th 2013 at 04:38 PM.
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  7. #7
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    Re: Logic puzzle - Need some help

    Both of them are lying?
    Last edited by John540; October 27th 2013 at 04:57 PM.
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