Two non-ideal heat engines operate in series. Engine I receives 1.0×103J of heat from a 600K reservoir and rejects its waste heat to an intermediate reservoir at 400K. Engine II uses this waste heat as its input and rejects heat to a 300K sink. Each engine operates at 60% of the efficiency of a Carnot engine working between the same two reservoirs. Calculate the total work produced by the combined arrangement in one complete cycle.
a) 4.0×102J
b) 3.2×102J
c) 2.0×102J
d) 2.8×102J