Learning Goal: I’m working on a chemical engineering exercise and need an explan

Learning Goal: I’m working on a chemical engineering exercise and need an explanation and answer to help me learn.I didn’t understand the Highlighted part ..How can The efficiency of this heat engine be 100% if 85 KJ of Energy somehow transferred back to Heat reservoir? Can you Please explain more brefily by using equation of Heat work and change in Internal energy (just using 1st law of thermodynamics)..
Requirements: short   |   .doc file