posted by Looking for someone to check my answer .
Basic Concepts of Probability and Counting
1. License plates are made using 3 letters followed by 2 digits. How many different plates can be made if repetition of letters and digits is allowed?
(26^3)(10^2) = (17576)(100) = 1,757,600
a password consists of two letters followed by a five-digit number. how many passwords are possible if (a)there are no restriction and (b)none of the letters or digits can be repeated? what is the probability of guessing the password in one if there no restriction?