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The lesson is 'never try'

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by sanju09 » Sat Feb 21, 2009 3:42 am
There are 9 people in the room. There are two pairs of siblings within that group. If we choose two people, what is the probability that they will not be siblings?

Produce your own response, links :)
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by billzhao » Sat Feb 21, 2009 3:51 am
The probability ofchoosing the first sibling is 4/9 and the probability of choosing the second sibling is 1/8.

So the probability of choosing a sibling pair is 4/9*1/8=1/18

So the probability of not choosing a sibling pair is 1-1/18=17/18

What is OA?
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