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    This is relatively easy.. but on my 2 week holiday ive forgotten everything!!! Ok here we go...

    "In a class of 20 pupils, 7 are left handed and 13 are right handed. Five pupils are selected at random from the class: the order in which they are chosen is irrelevant. Find the number of possible selectionsin which of the five are left ahnded and 3 of the five are right handed...

    The answer is 6006, but i dont know how to get it!

    I did 20C5 etc etc over 5C2 etc etc... i cnt work it out!!!

    will rep any1 who can help

    Thanks in advance!!
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    Numbers of ways of choosing 2 from 7 multiplied by the number of ways of choosing 3 from 13.

    7C2*13C3=ANS
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    (Original post by LearningMath)
    Numbers of ways of choosing 2 from 7 multiplied by the number of ways of choosing 3 from 13.

    7C2*13C3=ANS
    Oh my dayz! i did everything BUT that.. for sum reason i fort the 20 was relevant!! Repped...
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    The first post is right but just in case you wanted further reassurance, you want 7 choose 2 times 13 choose 3 or equally, 7 choose 5 times 13 choose 10 since you're choosing the things you don't want in the latter answer.
 
 
 
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