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Homework Help: Disc Math. (Impossible to answer?)

  1. Nov 16, 2013 #1
    Is the question in the paint document flawed?

    The question says.
    How many socks must he take out to be sure that he has at least two black socks?

    The solution to this problem is..

    in case if all twelve pickings are brown....

    Well how can he be sure that all twelve pickings are brown? He cannot. All twelve of his first pickings may be brown but they may also be black. Therefore he cannot be sure that the 13th and 14th pickings are black or brown because it is impossible for the person to know if his first twelve pickings are black or brown.

    Attached Files:

    • FQ.jpg
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  2. jcsd
  3. Nov 16, 2013 #2


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    You are really overthinking a simple question. He turns the lights on after he's picked a certain number of socks. If he only picks 2 socks, he might or might not have 2 black ones. If he picks 13 socks he might or might not have 2 black ones. If he picks 14 he definitely will have 2 black socks. That's all.
  4. Nov 16, 2013 #3
    I'm not overthinking the problem, that is how I interpreted the problem.

    Re-edit. Nevermind I was reading it wrong.
    Last edited: Nov 16, 2013
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