Need DESPERATE HELP on Physics Problem!?

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A hydroeletric company finds that during the hours between mignight and 7:00 a.m. the demand for its power output is only 50% of capacity. However, during other hours the company's output cannot keep up with the peak demand. In order to fully utilize its hydroelectric resources, the company constructs a reservoir above its dam having an average height of 50m. During the hours of low demand, it uses four generators to operate pumps that fill the reservoir with water from the river at a rate of 4.0 x 10 to the fifth power kg/hr.

a. What is the total potential energy stored each night by this means?

b. If the generators are 100% effiecient, what is the power of each in kilowatts? In megawatts?

Use the equations: W = Fd, PE = mgh, and Power = W/t.

Good luck! First one to answer correctly and TELLS HOW THEY GOT THE ANSWER gets the 10 points (and feeling of great accomplishment)!

P.S. This is not a trick question.