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1. (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
2. (Original post by jckh12)
I HAVE IT!!!

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

What did you do there?
3. (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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4. (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?
5. (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?
6. (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
7. (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?
8. (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)
9. (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
10. (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
11. (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
12. (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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