Rate at which heat supplied to the heat engine

  A Carnot heat engine receives heat at 800 K and rejects the waste heat at 350 K. Seventy five percent of work output from the heat engine is used to power a Carnot refrigerator that removes heat from the -20 °C cold space at a rate of 400 kl/min and rejects heat to the same reservoir as the heat engine, at 350 K. Determine the rate at which heat supplied to the heat engine, and the total rate of heat rejected to the 300 K environment. (Watch "Combined Analysis -2")