The digital sum of a number is the sum of its digits.
The digital sum of a number is the sum of its digits. For how many of the positive integers 24-100 inclusive is the digital sum a multiple of 7?
Answer/Solution
11
Steps/Work
is there other way than just listing?
25
34
43
52
59
61
68
70
77
86
95
11 ways..
B
25
34
43
52
59
61
68
70
77
86
95
11 ways..
B