Convert n(n-1)(n-2) into a factorial.

Question

Please show the method.

Answer 1

If it were n(n-1)(n-2)...(2)(1) it would be n!, i.e. "n factorial."

 

But you can see that lots of the 'tail-end' factors are missing.  So the answer is n! divided by (n-3)! -- that is, factors from (n-3) and so forth down to 1 are killed off by dividing by "(n-3) factorial."