math
posted by michael .
Determine the number of permutations of the letters of the word "EFFECTIVE"

Rewrite the word as:
"ceeeffitv" we see that it is a 9 letter word in which the letters e and f repeat 3 and 2 times respectively.
The number of permutations is therefore
9!/(3!2!1!1!1!1!)
=30240