A centrifugal ballast pump has a capacity of 200 gpm. If suction is taken on a ballast tank containing 200 long tons of seawater, how much water will be remain in the tank after discharging for one hour?

Correct Answer: Option C — 154.16 long tons

Discharging at 200 gallons per minute for one hour removes 12,000 gallons of seawater. Since one long ton of seawater equals approximately 261.8 gallons (based on 35 cubic feet per ton and 7.48 gallons per cubic foot), the pump discharges 45.84 tons, leaving 154.16 long tons in the tank.