A computer password is required to be 5 characters long. How many passwords are possible if the password requires 2 letter(s) followed by 3 digits (numbers 0-9), where no repetition of any letter or digit is allowed?

Answer 1

well I will do digits and you can do the letters the same way and then multiply
you have 10 digits
first one -- 10 choices
second one --- 9 choices
third one ---- 8 choices
so 10*9*8
now the letters :)