A closed system executed reversible cycle 1-2-3-4-5-6-1 consisting of six processes. During processes 2 and 3-4 the system receives 1000 kJ and 800 kJ of heat respectively at constant temperatures of 500 K and 400 K, respectively. Processes 2 and 4 are adiabatic expansions in which the steam temperature is reduced from 500 K to 400 K and from 400 K to 300 K respectively. During process 5-6 the system rejects heat at temperature 300 K. Process 6-1 is adiabatic compression process. Determine the work done by the system during the cycle and thermal efficiency of the cycle.