Oil is poured into a tank so that the tank is being filled at the rate of 4 cubic feet per hour. If the empty rectangular tank is 9 feet long, 8 feet wide, and 5 feet deep, approximately how many hours does it take to fill the tank? Pick one:  A) 60  B) 70  C) 80  D) 90  E) 100

Rationale: the volume the tank is : length * width * depth = 9 * 8 * 5 = 360 cubic feet . 360 cubic feet / 4 cubic feet per hour = 90 hours . it will take 90 hours to fill the tank . the answer is d .
Answer: D