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Algebra

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Joined:	23 Dec 2007
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27 Dec 2007 21:19:10 IST

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Permutation & combination

None

In how many ways 5 boys & 5 girls be arranged so that at least 2 girls are together?

I know one answer

10! - 5! x 6!

In this answer we substracting the unfavourable case that is grils will not be together.

But what if we want to take the favourable case?

I have taken the favourable cases as follows

2 girls will be together, 3 girls will be together, 4 girls will be together & 5 girls will be together , but both the answers are not matching.

SO CAN ANYONE HELP ME FOR THAT?

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Comments (3)

Purav Master

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Joined: 9 Nov 2006

Posts: 814

27 Dec 2007 22:47:18 IST

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That way also you will get the same answer. Why waste time???????

Rajesh Peter

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Joined: 14 Aug 2007

Posts: 22

28 Dec 2007 19:01:20 IST

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the problem is that when u consider the case of 3 gals being together u will be counting the case when 2 gals are together again.

svj 29

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Joined: 27 Dec 2007

Posts: 822

28 Dec 2007 19:09:22 IST

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i too agree with m.mannattil

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