Question

A valid password on a Web site contains 2 letters (A-Z, 26 total), followed by 3 digits (0-9). Letters and numbers can be repeated. The number of possible passwords equals _____.

Answer 1

To determine the number of possible passwords one can make out of the conditions in the given, we use the Fundamental Principles of Counting. There are 26 letters that can be used for the first character of the password. The same holds true for the second character. For the next three characters, there are 10 possible numbers in each slot. Multiplying the five numbers, we get 676,000. Hence, one can make 676,000 passwords.