A pump raises 500 kg of water through a vertical height of 12 m every minute. Taking g = 10 m/s², what is the minimum power of the pump?

Work done per minute = mgh = 500 × 10 × 12 = 60,000 J. Power = Work/time = 60,000 J / 60 s = 1000 W. Option A results from dividing by 600 instead of 60, option C results from forgetting to divide by time (60 s), and option D is the total work done without converting to power.