Coins are dropped into a toll box so that the box is being filled at the rate of approximately 2 cubic feet per hour. If the empty rectangular box is 4 feet long, 4 feet wide and 3 feet deep, approximately how many hours does it take to fill the box?

GMAT QUANT Problem Solving Difficulty: 600-700 Level, Geometry, Cube, ratio

Coins are dropped into a toll box so that the box is being filled at the rate of approximately 2 cubic feet per hour. If the empty rectangular box is 4 feet long, 4 feet wide and 3 feet deep, approximately how many hours does it take to fill the box?

(A) 2
(B) 8
(C) 16
(D) 24
(E) 48