Air enters the compressor of an ideal gas refrigeration cycle at 12C and 50 kPa and the

Question:

Air enters the compressor of an ideal gas refrigeration cycle at 12°C and 50 kPa and the turbine at 47°C and 250 kPa. The mass flow rate of air through the cycle is 0.08 kg/s. Assuming variable specific heats for air, determine,
(a) The rate of refrigeration,
(b) The net power input, and
(c) The coefficient of performance.