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    (Original post by TenOfThem)
    Ok ... You are getting there ������

    Now ... What do you do with probabilities if all 5 things need to happen?

    I HAVE IT!!!

    8/11x7x10 +3/11x2/10x1/9 -5/11 = 2/33
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    (Original post by jckh12)
    I HAVE IT!!!

    8/11x7x10 +3/11x2/10x1/9 -5/11 = 2/33
    Erm, no

    What did you do there?
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    (Original post by TenOfThem)
    Erm, no

    What did you do there?
    Oh then I don't know what to do next then ;/


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    (Original post by jckh12)
    Oh then I don't know what to do next then ;/


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    Ok ... No worries

    If you want things to happen together you have to multiply the probabilities

    So the probability of MMFFF = 8/11 x 7/10 x 3/9 x 2/8 x 1/7 = 2/330

    Now ... The same probability occurs for different arrangements of MMFFF

    So the probability of, for example, MFFMF is also 2/330

    There are 10 arrangements of MMFFF so 10 x 2/330 = 2/33

    However ... My new question is ... Do you know how I worked out the 10 for the different arrangements?
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    (Original post by TenOfThem)
    Ok ... No worries

    If you want things to happen together you have to multiply the probabilities

    So the probability of MMFFF = 8/11 x 7/10 x 3/9 x 2/8 x 1/7 = 2/330

    Now ... The same probability occurs for different arrangements of MMFFF

    So the probability of, for example, MFFMF is also 2/330

    There are 10 arrangements of MMFFF so 10 x 2/330 = 2/33

    However ... My new question is ... Do you know how I worked out the 10 for the different arrangements?
    Is it because there is 5 on each stall and there is 2 stalls, so times them together gives you 10?
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    (Original post by jckh12)
    Is it because there is 5 on each stall and there is 2 stalls, so times them together gives you 10?
    No

    Have you done the binomial expansion?

    Or

    Have you been introduced to the nCr function
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    (Original post by TenOfThem)
    No

    Have you done the binomial expansion?

    Or

    Have you been introduced to the nCr function
    Yes, how does that relate?
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    (Original post by jckh12)
    Yes, how does that relate?
    Because nCr gives you the number of arrangements when you have n items, r of one type

    So arrangements of MMFFF is 5C2 (or 5C3)
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    (Original post by TenOfThem)
    Because nCr gives you the number of arrangements when you have n items, r of one type

    So arrangements of MMFFF is 5C2 (or 5C3)
    Oh yeah ok, I get that
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    (Original post by jckh12)
    Oh yeah ok, I get that
    So
    P(A) = 8/11 x 7/10 x 3/9 x 2/8 x 1/7 x 5C2 = 2/33
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    (Original post by TenOfThem)
    So
    P(A) = 8/11 x 7/10 x 3/9 x 2/8 x 1/7 x 5C2 = 2/33
    I cant thank you enough, I would have never came to working out the solution without your help. Thanks for all your help and your patients
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    (Original post by jckh12)
    I cant thank you enough, I would have never came to working out the solution without your help. Thanks for all your help and your patients
    No problem

    Well done for sticking with it ... I could see you were getting frustrated at points
 
 
 
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