Well, honey, there are 8 nines in 72. Simple math, darling. Just divide 72 by 9 and you'll see there ain't no room for a ninth nine in there.
72
9*9=81 81-9=72 72/9=88
To find the 9s complement, subtract each digit from 9: 27 → 72
5
Nine of them
as in the multiples? 9 18 27 36 45 54 63 72 81 90 99 ...
79
9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108
The pattern is: 9, 18, 27, 36, 45, 54, 63, 72, 81, and 108.
10 times
Eleven.
Exactly 6 of them