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I have $N$ items with a number on them, ranked $1,2,3,4,5,\dots,N$, and I select $P$ items at random.

What are the chances that 3 of the top 5 numbered items are in the $P$ chosen items?

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    In how many ways can we select $P$ items from $N$ items? And in how many ways can we select $P$ items from $N$ items such that $3$ of those $5$ (and $P - 3$ of the remaining $N - 5$) are picked?2012-03-25
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    Exactly three , or at least three of the top 5?2012-03-25
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    *at least three of the top 5. Thanks.2012-03-25

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