How many numbers less than 100 have sum of their digits completely division by 9?

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answers:
sepia say: 11
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Jeffrey K say: Eleven
This is true for every multiple of 9
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Krishnamurthy say: Numbers less than 100 having sum of their digits completely divisible by 9:
9, 18, 27, 36, 45, 54, 63, 72, 81, 90 and 99 (Total: 11)
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cryptogramcorner say: So, lets assume that you mean integers in the range 1 through 99

The biggest possible number is 99, and 9 + 9 = 18 is divisible by 9
All other sums be less than 18, so now we only need to look for sums that add up to 9,

9 by itself works. all that is left is 2 digits numbers whose digits all up to 9

18
27
36
45
54
63
72
81

and 90

So count up all those cases. If you need to include 0, that's one more.
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Pope say: I cannot know whether you are including zero or negative numbers. For that matter, how do I know if you are restricting it to integers? The sum of the digits of an integer is divisible by nine if and only if the integer itself is divisible by nine. See if that helps.
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Φ² = Φ+1 say: I cannot count all those negative numbers that are completely divisible by 9.
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fmcwo say: tlgeltoe
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zweix say: lcgvnljq
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