Question

Customer account "numbers" for a certain company consists of 3 letters followed by 3 single-digit numbers. How many different account numbers are possible if repetitions of letters and digits are allowed?

Answer 1

There are 26 possible choices for each of the 3 letters and 10 possible choices for each of the 3 single-digit numbers. Therefore, the total number of possible account numbers is:

26 * 26 * 26 * 10 * 10 * 10 = 17,576,000

So, there are 17,576,000 different account numbers possible for this company.