exergy of the steam at inlet

Steam enters a turbine steadily at 3.2MPa and 440°C at a rate of 9 kg/s and exits at 0.18MPa and 144°C. The steam is losing heat to the surrounding air at 100 kPa and 25°C at a rate of 280 kW. Calculate (a) exergy of the steam at inlet, (b) the actual power output, (c) the maximum possible power output, (d) the second law efficiency, and (e) the exergy consumed.