(i) Power `= E/t`
Work doneby the pump is utilized to lift the water to a height of 10 m. That is the energy stored in the form of potential energy.
But potential energy `= mgh`.
By substituting the value of power, height, time and accleration due to gracvity, we can determine the mass of the water.
(ii) `2.984 kWh, 107424 kg`.