Can You Free the Lady in the Cage?
(a riddle)

  
    There is a lady in a cage that is guarded by two men.  One of the guards always lies.  The other always tells the truth.  Unfortunately, you have no idea who is the truthful one; and you cannot direct your question by saying something like, "I want the one who always speaks the truth to answer this."  So you'll have to ask your question not knowing whether the one who answers it is the one who speaks the truth or not.

    On the outside of the cage are two unlabeled buttons: one will open the door to set the lady free, but the other will electrocute her (and you don't know which is which).

    To find out the right button to push, you can ask only one question -- and to only one of the guards. What would that question be?

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    Though I don't remember the exact wording of it, I heard this riddle about 10 years ago or more.  Someone once said that it had been on a "Dr. Who" episode, but I don't know if that would be where it actually originated.

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    If you'd like to see the answer, click here.