A computer password is required to be 7 characters long. How many passwords are possible if the password requires 2 letter(s) followed by 5 digits (numbers 0-9), where no repetition of any letter or digit is allowed?

Answer 1

Possible 2 letters: 26*25
possible 5 digits : 10*9*8*7*6

so possible passwords = 26*25*10*9*8*7*6
= ....