Issue is '0'. Since it is not allowed as the first digit, we are forced to take one among 1-9. Now, this makes the selected digit not being among the unit digit. We have 5 odd digits - 1, 3, 5, 7, 9 which can be eliminated like this but only 4 even digits can be eliminated 2, 4, 6, 8. Thus among all the possible numbers, even numbers will be more than odd numbers.