How many permutations are there in the word QUALIFY if the letters are taken 5 at a time
7! / 5! * 2! = 21
7!/ [7 - 5]! = 7 x 6 x 5 x 4 x 3 =7! / 2! =2,520
Permute any 5 letters chosen from 7 = P (7,5) = 2520
