Question

how many 9 digits are there upto 1 to 100

Answer 1

hey friend ,let us start ,

09,19,29,39,49,59,69,79,89,99

in this case there are 11 9's

now,
90,91,92,93,94,95,96,97,98
there are 9 9's

so total 20. 9's are there between 1 and 100