Find The rate of fuel injection in mg/s through each hole of a four hole injector fitted in the engine cylinders

Question

A six cylinder four stroke CI engine developing a power output of 270 kW at 1000 rmp has a fuel consumption of 0.25 kg/kWh. The injection takes place over 20⁰ crank angle with pressure across the injector orifice of 100 MPa. Find.

(i) The rate of fuel injection in mg/s through each hole of a four hole injector fitted in the engine cylinders, and

(ii) Thermal efficiency of the engine