The first letter can be any one of 26 letters. For each one . . .
The second letter can be any one of 26 letters. For each one . . .
The first digit can be any one of 10 digits. For each one . . .
The second digit can be any one of 10 digits. For each one . . .
The third digit can be any one of 10 digits. For each one . . .
The fourth digit can be any one of 10 digits. For each one . . .
The fifth digit can be any one of 10 digits.
The total number of possibilities is
(26 x 26 x 10 x 10 x 10 x 10 x 10) =
( 26² x 10⁵) = (676 x 100,000) = 67,600,000 .
