A homologous series of centrifugal pumps has a specific speed of 1.1 and are driven by 2400-rpm motors. For a 400-mm size within this series, the manufacturer claims that the best efficiency of 85% occurs when the flow rate is 500 L/s and the head added by the pump is 895 m. What would be the best-efficiency operating point for a 300-mm size within this homologous series, and estimate the cor- responding efficiency
