Tanks M and B are each in the shape of a right circular cylinder. The interior of tank M has a height of 10 meters and a circumference of 8 meters, and the interior of tank B has a height of 8 meters and a circumference of 10 meters. The capacity of tank M is what percent of the capacity of tank B?
Choose the correct choice from the following choices:
A) 75 %
B) 80 %
C) 100 %
D) 120 %
E) 125 %

Rationale: b . for m , r = 8 / 2 pi . its capacity = ( 4 pi ) ^ 2 * 10 = 160 pi for b , r = 10 / pi . its capacity = ( 5 pi ) ^ 2 * 8 = 200 pi m / b = 160 pi / 200 pi = 0.8
Answer: B