SOLUTION: P(n,n-1)=6

Question 1177997: P(n,n-1)=6

Answer by greenestamps(13200) (Show Source): You can put this solution on YOUR website!

By definition, P(n,n)=n!

P(3,3) = 3*2*1 = 3!
P(5,5) = 5*4*3*2*1 = 5!
etc...

What about P(n,n-1)?

P(3,2) = 3*2 = 6 = 3!
P(5,4) = 5*4*3*2 = 120 = 5!
etc...

The only difference between P(n,n-1) and P(n,n) is an additional factor of 1, which of course doesn't change the result.

So P(n,n-1) = n!

Then your problem is to solve

P(n,n-1) = 6 = n!

By inspection, n = 3.

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