A Carnot heat engine receives heat at 750 K and rejects the waste heat to the environment at 300 K. The entire work output of the heat engine is used to drive a Carnot refrigerator that removes heat from the cooled space at -15^∘C at a rate of 400 kJ/min and rejects it to the same environment at 300 K. Determine:

(a) The COP of the refrigerator.

(b) The absolute value of the power in kJ/min.

(c) Efficiency of the heat engine.

(d) The rate of heat supplied to the heat engine in kJ/min.