Thursday, May 16, 2013

the number of ways of arranging 5 women and 4 men so that the row begin and end with women


Question 749359 in Permutations:
the number of ways of arranging 5 women and 4 men so that the row begin and end with women

5-ways to choose 1st person
4-ways to choose the last
(7)(6)(5)(4)(3)(2)(1) ways to choose middle people

total: 20(7!)=10800

:)

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