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A certain junior class has 1000 students and a certain

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Joined: 31 Mar 2006
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20 May 2006, 04:45
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

A certain junior class has 1000 students and a certain senior class has 800 students. Among these students, there are 60 sibling pairs eac consisting 1 junior and 1 senior. If 1 student is to be selected at random from each class, what is the probabilty that the 2 students selected will be a sibling pair?

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Joined: 16 Aug 2005
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20 May 2006, 04:57
This has been discussed many times before:

Total pairs = 1000x800
Out of which sibling pairs = 60

So, probability = 60/800000 = 3/40000
20 May 2006, 04:57
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A certain junior class has 1000 students and a certain

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