Math word problems.

Question

A pump Removes 30 gallons of water per minute is pumping water from a cellar 30 x 50 feet covered with eight inches of water. One cubic foot of water equals 7.5 gallons of water. The number of minutes it will take to remove the eight inches of water from the cellar is, MOST NEARLY. . . A. 200 B. 225 C. 250 D. 275

Answer 1

Since a cubic foot of water is 7.5 gallons of water, 8 inches (which corresponds to 2/3 of a cubic foot of water) equals 5 gallons of water. Since the area of the cellar is 30 * 50 = 1500 sq feet then 1500 * 5 = 7500 is the amount of water in the cellar. So if water is removed at a rate of 30 gallons per minute then 7500/30 = 250 is the number of minutes it would take to remove all of the water from the cellar.

Answer 2

V_removed = (30)(50)(2/3) ft³

V_removed = 1000 ft²

gal. = (1000 ft³)(7.5 ga/ft³)

gl = 7500

7500 gal / 30 gpm = 250 min