Approximately how many cubic feet of water are needed to fill a circular swimming pool that is 40 feet across and 7 feet deep?	Pick:
A) 700  B) 1500  C) 3000  D) 5000  E) 9000

Rationale: "answer should be e . v = \ pir ^ 2 h = \ pi * 20 ^ 2 * 7 = approximately 9000"
Answer: E