Including the one in ' 1 ' and the one in '100', there are 21 1s.
Every other digit 2 - 9 appears 20 times between 1 and 100 .
120 times.
With a total of 90,000 five digit numbers, we can conclude that there is 45,000 EVEN five digit numbers.
12 numbers
There are only 999 three digit whole numbers.
Only one . . . 999 .
11 times
As a digit in other numbers it appears 20 times
Infinitely many.
18
20000 times
A total of 44 times.
18 times
200
200
16
700000
It appears 25 times.