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? Choose the correct choice from the following options:
A) 7
B) 11
C) 14
D) 16
E) 20
is there other way than just listing?   25   34   43   52   59   61   68   70   77   86   95   11 ways..   11
<result>B</result>
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?