<PRE><B>Question 383202</B>
The set of permutations of {1,3,5} is simply the set of all possible ways of arranging {1,3,5}. These are


{1,3,5}, {1,5,3}, {3,1,5}, {3,5,1}, {5,1,3}, {5,3,1}


Since there are 6 items in this collection, this means that there are 6 permutations.



A quick way of computing this is to simply calculate 3! to get 3! = 3*2*1 = 6

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Recall that 


n P r = (n!)/(n-r)!


So in this case, n = 7 and r = 3, which means that 


7 P 3 = (7!)/(7-3)! = (7*6*5*4!)/(4!) = 7*6*5 = 210



So 7 P 3 = 210</PRE>