6
-1
There are 3 whose sum is 45 whose sum is 57 whose sum is 69 whose sum is 711 whose sum is 813 whose sum is 915 whose sum is 1017 whose sum is 1119 whose sum is 1219 whose sum is 1317 whose sum is 1415 whose sum is 1513 whose sum is 1611 whose sum is 179 whose sum is 187 whose sum is 195 whose sum is 203 whose sum is 211 whose sum is 22.
There are nine(9) numbers: 19, 28, 37, 46, 55, 64, 73, 82, 91
Nine hundred thirty (930) is the highest three digit number whose digits have a sum of 12. 9+3+0=12. Any numbers higher than that will give you an sum greater than 12.
6
There are no 3-digit whole numbers whose digits sum to 3. The smallest 3-digit number is 100, and the largest is 999, but in neither case is the sum of the digits equal to 3.
450.
69
There are infinitely many. For example, 14,104,1004,10004,100004 etc.
10
-1
999 are whole.
3,612,345,678
There are 3 whose sum is 45 whose sum is 57 whose sum is 69 whose sum is 711 whose sum is 813 whose sum is 915 whose sum is 1017 whose sum is 1119 whose sum is 1219 whose sum is 1317 whose sum is 1415 whose sum is 1513 whose sum is 1611 whose sum is 179 whose sum is 187 whose sum is 195 whose sum is 203 whose sum is 211 whose sum is 22.
There are nine(9) numbers: 19, 28, 37, 46, 55, 64, 73, 82, 91
there are so many,62; 26; 17; 71; 1,000,200,4001; 8,000; 1,232; 44; 611; 431, etc.