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Math Help - probability

  1. #1
    Member GAdams's Avatar
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    probability

    There are more than four coins in my pocket. The total value of them is 25p. I pick a coin at random. The probability that will take out a 1p is 1/4.
    How many, and which coins do I have in my pocket?
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  2. #2
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    This are British coins right?
    Otherwise there is no solution for US coins. Cause there is no 2cent-coin around here, or I haven't seen one

    -O
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  3. #3
    Member GAdams's Avatar
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    Quote Originally Posted by oswaldo View Post
    This are British coins right?
    Otherwise there is no solution for US coins. Cause there is no 2cent-coin around here, or I haven't seen one

    -O
    Yes, British coins.
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  4. #4
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    Probability

    Hello GAdams
    Quote Originally Posted by GAdams View Post
    There are more than four coins in my pocket. The total value of them is 25p. I pick a coin at random. The probability that will take out a 1p is 1/4.
    How many, and which coins do I have in my pocket?
    The number of coins must be a multiple of 4, otherwise the probability of taking out a 1p coin could not be exactly 1/4.

    So, with 8 coins, a solution is: 10, 5, 2, 2, 2, 2, 1, 1

    There may be other solutions. I haven't tried any others.

    Grandad
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