Question 499018
2 letters: 26^2 = 676.
3 digits: I assume no repeats means immediate, e.g. 121 is OK.
Then free choice 10 * slighlty restricted 9 * similar 9 = 810
Total = 676 * 810 = 547,560.
If the assumption is wrong, that part is 10*9*8 --> 720 --> 486,720.