Answer
$58,500$
Work Step by Step
There are 26 letters in the alphabet, and there are 10 different digits.
The first letter in the code can be any letter of the alphabet =26 choices
The second letter in the code can not be the same as the first letter, but can be any other: 25 choices.
The first digit in the code can not be 0, but can be any other digit: 9 choices.
The second digit can be any digit, that is 10 choices
Therefore the number of different codes is $26*25*9*10=58,500$
58,500 different customers can be identified.
