Water is leaking out from a cylinder container at the rate of 0.31 m^3 per minute. After 10 minutes, the water level decreases 9 meters. What is value of the radius in meters?	Choose the correct choice from the following answers
A) 1 / 2
B) 1 / 3
C) 1.5
D) 3
E) 6

Rationale: 10 * 0.31 = 3.1 = pi * r ^ 2 * h r ^ 2 = 3.1 / ( pi * 9 ) which is about 1 / 9 r = 1 / 3 the answer is b .
Answer: B