How many different numbers are possible?

Question

A personal identification number consists of 3 letters followed by 3 digits. The letters X,Y, and Z are not used and the last digit cannot be 0 or 9.

__?__ different numbers

Answer 1

You don’t specify whether a number or letter can be reused. I will assume that they can so you have 23 choices for each of the first 3 slots and 8 choices for each of the la 3 so the total number is

23 x 23 x 23 x 8 x 8 x8= 6229504

Answer 2

₂₃P₃ * ₁₀P₂ * 8 where the P's are the number of permutations