A pump has a suction condition of 50 mm Hg vacuum pressure, 100 mm diameter pipe, and a discharged condition of 250 kPa at a 90 mm diameter. The discharge tank is 50 m elevation and the suction is 5 m below the pump center line. If the discharge is 0.20 m^3/s, find the pump efficiency for 260 kW brake power.
a. 74.32% b. 77.12% c. 79.23% d. 82.455