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Math Help - Solve This and you'll get a date with me

  1. #1
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    Solve This and you'll get a date with me

    A Crime Story
    An elementary school teacher had her purse stolen. The thief had to be Lilian, Judy , David, Theo, or Margaret. When questioned, each child made three statements :

    Lilian :
    (1) I didnít take the purse.
    (2) I have never in my life stolen anything.
    (3) Theo did it.

    Judy :
    (4) I didnít take the purse
    (5) My daddy is rich enough, and I have a purse of my own.
    (6) Margaret knows who did it.

    David:
    (7) I didnít take the purse.
    (8) I didnít know Margaret before I enrolled in this school.
    (9) Theo did it.

    Theo :
    (10) I am not guilty.
    (11) Margaret did it.
    (12) Lilian is lying when she says I stole the purse.

    Margaret:
    (13) I didnít take the teacherís purse.
    (14) Judy is guilty.
    (15) David can vouch for me because he knows me since I was born.

    Later, each child admitted that two of his statements were true and one was false. Assuming this is true, who stole the purse?
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  2. #2
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    Berkeley, Illinois
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    Quote Originally Posted by hotgal24 View Post
    A Crime Story
    An elementary school teacher had her purse stolen. The thief had to be Lilian, Judy , David, Theo, or Margaret. When questioned, each child made three statements :

    Lilian :
    (1) I didnít take the purse.
    (2) I have never in my life stolen anything.
    (3) Theo did it.

    Judy :
    (4) I didnít take the purse
    (5) My daddy is rich enough, and I have a purse of my own.
    (6) Margaret knows who did it.

    David:
    (7) I didnít take the purse.
    (8) I didnít know Margaret before I enrolled in this school.
    (9) Theo did it.

    Theo :
    (10) I am not guilty.
    (11) Margaret did it.
    (12) Lilian is lying when she says I stole the purse.

    Margaret:
    (13) I didnít take the teacherís purse.
    (14) Judy is guilty.
    (15) David can vouch for me because he knows me since I was born.

    Later, each child admitted that two of his statements were true and one was false. Assuming this is true, who stole the purse?

    I think Judy jacked the purse. If I'm right, I'll tell you how I figured that out. Also, If I'm right, I'll pass on the date
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  3. #3
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    Just look at Lilian and Theo. One statment by Lilian is false. Say that (3) is true. Then Theo did it. Now two statement Theo says have to be true then, but all three are false. Which is against the rules. Thus, out assumption that (3) is true must be false. Thus, Theo is not the theif. Now look at Theo's statements. Again two must be true and one must be false. (10) and (12) are true, so (11) is false, meaning Margaret did not do it. Look at David. If he took the purse then statements (7) and (9) are false, against our rules. Thus, he did not do it. This just leaves Judy.
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  4. #4
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    Alfaz del Pi Spain
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    Wink

    I agree that it its JUDY

    Reason:

    Everyone except Judy names who they think is the real theif.

    Each person lied once

    e.g.

    Lilian :
    (1) I didn’t take the purse. TRUE
    (2) I have never in my life stolen anything. TRUE
    (3) Theo did it. FALSE


    ONLY Judy gets away with it...

    Judy :
    (4) I didn’t take the purse FALSE - She doesnt blame anyone else so the other 2 could be true.
    (5) My daddy is rich enough, and I have a purse of my own. TRUE
    (6) Margaret knows who did it. TRUE




    Using that information lets see if im right... it all balances out.

    Lilian :
    (1) I didn’t take the purse. TRUE
    (2) I have never in my life stolen anything. TRUE
    (3) Theo did it. FALSE

    Judy :
    (4) I didn’t take the purse FALSE
    (5) My daddy is rich enough, and I have a purse of my own. TRUE
    (6) Margaret knows who did it. TRUE

    David:
    (7) I didn’t take the purse. TRUE
    (8) I didn’t know Margaret before I enrolled in this school. TRUE
    (9) Theo did it. FALSE

    Theo :
    (10) I am not guilty. TRUE
    (11) Margaret did it. FALSE
    (12) Lilian is lying when she says I stole the purse. TRUE

    Margaret:
    (13) I didn’t take the teacher’s purse. TRUE
    (14) Judy is guilty. TRUE
    (15) David can vouch for me because he knows me since I was born. FALSE


    NICE Question
    Last edited by Stone Cold; March 25th 2008 at 10:47 AM.
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  5. #5
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    Lilian couldn't have done it. If she did she lied three times not once which we presume is false. So it is true that she didn't take the purse. Either she has never stolen something is true or Theo did it is true. But Theo couldn't have done it since then he would have lied twice.

    So Theo didn't do it, then neither did Margaret by Theo's statements. So when she says she didn't do it shes telling the truth. Thus either Judy did it or David has not known Margaret since birth. If David has known Margaret since then he must have taken the purse but then that contradicts the assumption that Margaret was lying only about knowning David since birth. Therefore Judy must have done it.
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