If y > 0, (7y)/20 + (3y)/10 is what percent of y? Choose the correct choice:
A) 40 %
B) 50 %
C) 65 %
D) 70 %
E) 80 %

Rationale: "can be reduced to 7 y / 20 + 6 y / 20 = 13 y / 20 = 65 % answer c"
Answer: C