You can put this solution on YOUR website! From x00 to x00 there are 9
from x10 to x19 there are 8
from x20 to x29 there are 7
from x30 to x39 there are 6
from x40 to x49 there are 5
from x50 to x59 there are 4
from x60 to x69 there are 3
from x70 to x79 there are 2
from x80 to x89 there are 1
from x90 to x99 there are 0
Total per each hundred = 45
There are 9 possible digits for x, so 9 x 45 = 405
ANSWER: There are 405 3 digit numbers whose units digit is greater than the tens digit.
