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    ok so here goes...

    In a village of 30 people 10 support blue and 20 support red
    In a sample of 10 what is the probability that exactly 7 support red

    just a pointer would be good

    thanks
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    How many ways of choosing a sample of 10 from 30 people?
    How many ways of choosing 7 red from 20 and 3 blue from 10?
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    (Original post by DFranklin)
    How many ways of choosing a sample of 10 from 30 people?
    How many ways of choosing 7 red from 20 and 3 blue from 10?
    so i have (30c10), (20c7) and (10c3)

    so now do i do (20c7)x(10c3)/(30c10)??

    so i get 0.31?
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    Yes.
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    thanks
 
 
 
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Updated: February 7, 2010
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