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Liars and Truth Tellers

  1. Apr 17, 2006 #1
    Here's a variation on the story I had not seen before. A man, who is dying, is in a bar. Two women are seated at a table. One always tells the truth and the other always lies. In front of the women are two glasses, one contains a drink that will cure the man, the other a poison that will kill him. What one question should he ask?
  2. jcsd
  3. Apr 17, 2006 #2
    Point to drink #1 and ask woman #1, "Would woman #2 say this drink would cure me?" If the answer is no, drink that one. If she says yes, drink the other one. Not much of a variation.
  4. Apr 17, 2006 #3


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    Tell both women to take a sip of their respective drink.
  5. Apr 17, 2006 #4


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    I heard the same 1 abut a prisoner and exit door.
    Nice 1!
  6. Apr 17, 2006 #5
    Yes, but you're supposed to ask one a question, not tell both of them to do something. Neither is obligated to do something, but each is obligated to always answer (since it says each always lies or always tells the truth).
  7. Apr 17, 2006 #6
    That'a the best answer I've seen. I had just never heard the problem phrased in this way.
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