### Instruction: If 28a+30b+31c=365.
then a+b+c=?.a,b,c are natural numbers
Answer Choices: (A) 9 (B) 10 (C) 11 (D) 12 (E) 13.### Response: Let's reason about the multi-choice question.
have a look on your calender
since,we all knw a year consist of 365 days
february is d only month which has 28 days
4 months in a year has 30 days
and,rest 7 months has 31 days..
so,following d given eq. we can write 28*1 + 30*4 + 31*7..
hence values of a,b and c are 1, 4 and 7 respectively..
a+b+c=12
The answer is D