A small business assigns account numbers for regular clients as follows. An acco
ID: 3220608 • Letter: A
Question
A small business assigns account numbers for regular clients as follows. An account number consists of six symbols. The first two symbols are taken from the letters A,B,C, ... , Z and the last four symbols are from the digits 1,2,3,4,5,6,7,8,9. The digit 0 is not allowed as it is too often confused with the letter O. To illustrate, one possible account number is AA2117.
a. How many different account numbers are possible?
b. How many different account numbers can be made by rearranging the symbols AB3522, still using the two letters followed by 4 digits format?
Explanation / Answer
(a) There are 26 * 26 * 9 * 9 * 9 * 9 = 4435236 account numbers possible
(b) There are 2 * 16 = 32 account numbers possible