A hydraulic turbine-generator is used to generated electricity and installed at a site 80 m below the free surface of a large water reservoir that can supply water at a volume flow rate of 1.4 m³/s steadily. If the mechanical power output of the turbine is 890 kW and the electric power generation is 790 kW, determine (a) the turbine and the generator efficiencies. (b) the combined turbine-generator efficiency of this plant. Neglect losses in the pipes.