A centrifugal pump with four stages in parallel delivers 180 I/s of water against a manometric head of 25 m, the diameter of the impellers is 23 cm, and the pump's speed is 1700 rpm. Another pump is...

A centrifugal pump with four stages in parallel delivers 180 I/s of water against a manometric head of 25 m, the diameter of the impellers is 23 cm, and the pump's speed is 1700 rpm. Another pump is to be designed with a number of stages in series, of similar construction to those of the first pump (same specific speed), to run at 1250 rpm and to deliver 240 I/s against a manometric head of 245 m. Find the diameter of the impellers and the number of stages required