A steam generator in a power plant consists of two separate heat exchanger devices: a boiler which converts compressed liquid water to saturated vapor, and a super-heater which adds additional thermal energy to the steam converting it to a superheated vapor. The thermal energy for both devices is supplied by combustion of coal which has a heating value of 15 MJ/kg. Both the boiler and super-heater are isobaric at a pressure of 5 MPa. Water enters the boiler at a mass flow rate of 10 kg/s at 150 °C and exits the super-heater at 600 °C. For this system determine a) the total rate of coal consumption (kg/s) Qin = mfuel * heating value of fuel, b) the fraction of the total coal mass used to operate the super-heater (%).