Solve the problem.
-How many different 3-letter codes are there if only the letters A, B, C, D, E, F, G, H, and I can be used and no letter can be used more than once?
A)504
B)3
C)729
D)84

Question

Quizplus · Accepted Answer

Since no letter can be used more than once and there are 9 different letters to choose from, the number of different 3-letter codes can be calculated using permutations: 9P3 = 9! / (9-3)! = 9*8*7 = 504.

Solve the Problem. -How Many Different 3-Letter Codes Are There If Only the If