Tanks A and B are each in the shape of a right circular cylinder. The interior of tank A has a height of 10 meters and a circumference of 7 meters, and the interior of tank B has a height of 7 meters and a circumference of 10 meters. The capacity of tank A is what percent of the capacity of tank B?  Choose one:
A) 70 %
B) 80 %
C) 100 %
D) 120 %
E) 125 %

Rationale: "the radius of tank a is 7 / ( 2 * pi ) . the capacity of tank a is 10 * pi * 49 / ( 4 * pi ^ 2 ) = 245 / ( 2 * pi ) the radius of tank b is 10 / ( 2 * pi ) . the capacity of tank b is 7 * pi * 100 / ( 4 * pi ^ 2 ) = 350 / ( 2 * pi ) tank a / tank b = 245 / 350 = 7 / 10 = 70 % the answer is a ."
Answer: A