It has been raining at the rate of 5 centimeters per hour. If the rain filled a cylindrical drum with a depth of 15 centimeters, and area 300 square centimeters, how long did it take to fill the drum completely?  Choose the correct choice
A) 3 hours B) 4 hours 15 minutes C) 6 hours D) 2 hours 5 minutes E) 8 hours

Rationale: answer is : a , 3 hours the volume of the drum is irrelevant and only height matters since rain fell all over the city . thus , it takes only 15 / 5 = 3 hours of rain to fill the drum
Answer: A