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 9 meters, and the interior of tank B has a height of 9 meters and a circumference of 10 meters. The capacity of tank A is what percent of the capacity of tank B?  Choose the most appropriate option.
A) 75 % B) 90 % C) 100 % D) 120 % E) 125 %

Rationale: "the radius of tank a is 9 / ( 2 * pi ) . the capacity of tank a is 10 * pi * 81 / ( 4 * pi ^ 2 ) = 405 / ( 2 * pi ) the radius of tank b is 10 / ( 2 * pi ) . the capacity of tank b is 9 * pi * 100 / ( 4 * pi ^ 2 ) = 450 / ( 2 * pi ) tank a / tank b = 405 / 450 = 9 / 10 = 90 % the answer is b ."
Answer: B