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# Boys and Girls Line Up

Best Answer Yoruichi-san, 03 July 2013 - 10:04 PM

Spoiler for Preliminary calculations give..
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Posted 03 July 2013 - 08:54 PM

Suppose that 7 boys and 13 girls line up in a row.  Let S be the number of places in the row where a boy and a girl are standing next to each other.  For example, for the row GBBGGGBGBGGGBGBGGBGG we have S = 12.  If all possible orders of these 20 people are considered, what is the average value of S?  Can you generalize this result to a group of m boys and girls?

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### #2 Yoruichi-san

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Posted 03 July 2013 - 10:04 PM   Best Answer

Spoiler for Preliminary calculations give..

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Women are definitely stronger. We are [Fe]males, after all...

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### #3 Barcallica

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Posted 06 July 2013 - 09:25 AM

Spoiler for

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### #4 bonanova

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Posted 07 July 2013 - 05:58 AM

Spoiler for part 1

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