Calculate the diameter and speed of the runner of a Kaplan turbine developing 6000 kW under

Calculate the diameter and speed of the runner of a Kaplan turbine developing 6000 kW under an effective head of 5 m. Overall efficiency of the turbine is 90%. The diameter of the boss is 0-4 times the external diameter of the runner. The turbine speed ratio is 2-0 and flow ratio 0-6. What is the specific speed of the turbine?