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Math Help - Plz Solve

  1. #1
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    Plz Solve

    There are 10 coins. 6 coins showing head. And 4 showing tail. Each coin was randomly flipped (not tossed) seven times successively.after flipping the coins are 5 heads 4 tails one is hided the hided coin will have what.
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by bharathlece
    There are 10 coins. 6 coins showing head. And 4 showing tail. Each coin was randomly flipped (not tossed) seven times successively.after flipping the coins are 5 heads 4 tails one is hided the hided coin will have what.
    The way this question reads it will be heads with probability 0.5 and tails with
    probability 0.5. But we must suspect that something else was intended, if so
    the intention has been lost somewhere.

    RonL
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  3. #3
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    i didnt understand ur replay

    on which basis ur going to say that head and tail has a probability of 0.5

    plz explain in detail.
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  4. #4
    Grand Panjandrum
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    Quote Originally Posted by bharathlece
    on which basis ur going to say that head and tail has a probability of 0.5

    plz explain in detail.
    That the coins are fair, and that flipping even once randomises a coins
    orientation. So knowledge of the orientation of the other coins tell you nothing
    about the orientation of the last coin, and after they have all been flipped
    at least once their orientations are unrelated and randomised.

    RonL

    RonL
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  5. #5
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    Hi:

    I am inclined to believe this to be a "trick question", its deception being drawn from its ambiguous delivery. At first reading, it seemed (to me) that the coins were gathered up from their initial positions as 6 H and 4T, and reflipped. The trickster, expecting the trickee to assume just that, further expects such assumption to confound his unsuspecting victim. But no mention of a reflip was made. That being the case, the hidden coin is facing heads up.

    Regards,

    Rich B.
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