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 5460 five digit numbers with a digit sum of 22.
6
6
I believe here are 51 such numbers.
10
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.
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.
37
I am not at all sure about "present". If you mean percent, the answer depends on which 100 numbers. Between 900 and 999, for example, the answer is 0%. For the FIRST 100 numbers: 1 to 100, the answer is 6%.
999 are whole.
Since we are talking for the sum of digits, then we are talking about 2-digit numbers between 1 and 100, which are 90 numbers (10 to 99). From these numbers only half of them satisfy the above condition, that is 45 numbers. So 50% of 2-digit numbers between 1 and 100 have an odd sum of their digits.
77
5050 ie 101 x 50
There are 5460 five digit numbers with a digit sum of 22.
6
53 is prime, and 5+3 = 8.