20!
9,19,29,39,49,59,69,79,89,90,91,92,93,94,95,96,97,98,99
Eleven.
11 with 1 remaining 100 - 1 = 99 = 9 x 11
111 of them with a remainder of 1
9^2+9+9 +9/9 81+9+9+1=100
9, 19, 29, 39, 49, 59, 69, 79, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 =20
Well there will be 1 nine for all the 9s in the units column (9, 19, 29 etc.), and 1 nine for all the numbers with 9 in the tens column (90, 91, 92 etc.). So the answer is 20.
There are: 640/9 = 71 with a remainder of 1
You can achieve a total of 100 using four 9s with the following equation: ( (99 + \frac{9}{9}) = 100 ). Here, 99 is formed by placing two 9s together, and the fraction ( \frac{9}{9} ) equals 1, which brings the total to 100.
9, 19, 29, 39, 49, 59, 69, 79, 89, 90, 91, 92
101
25 numbers are between 1-100.
100