The water in a large lake is to be used to generate electricity by the installation of a hydraulic turbine-generator at a location where the depth of the water is 50 m. Water is to be supplied at a rate of 5000 kg/s. If the electric power generated is measured to be 1862 kW and the generator efficiency is 95%, determine a) the overall turbine-generator efficiency, b) the mechanical efficiency of the turbine, and c) the shaft power supplied by the turbine to the generator.