A heat engine operates between two reservoirs, one at 1000 C and the other at 300 C. For every heat interaction of 1 kJ with the high-temperature reservoir, it rejects 0.6 kJ into the lowtemperature reservoir. (a) Is such an engine feasible? If yes, is it reversible? (b) If it rejects 0.3 kJ into the low-temperature reservoir, is it feasible?