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by dmateer25 » Tue Apr 28, 2009 5:54 am
Four individuals are selected from a group of 5 married couples. What is the probability that the selected four are 2 couples?


10C4 = total ways to select 4 from 10
10C4=210

Now there are 5C2 ways for them to be married couples. (5 married couples and you need 2 of them).

5C2 = 10



10/210 = 1/21
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by criszerriny » Wed May 06, 2009 5:19 am
hmm Shouldn't it be, 4C2/5C4?
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by mike22629 » Wed May 06, 2009 8:28 am
No, because the bottom the top of the equation he is grouping them as couples because only couples fit the restraint. On the bottom (total possible), there are 10 people that can be arranged in different ways.

1/21 seems correct
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