Enumerating Row Arrangements of Three Species
نویسندگان
چکیده
This problem nicely illustrates the use of factorials and has a simple solution, though students often neglect the factor of two in the answer 2(N !)2. This omission can be instructive, as it leads naturally to generalizations of the problem: How does the answer change if there are N men and N − 1 women? What if men outnumber women by 2 or more? What if a sexist photographer insists that the lineup start with a man?
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