Figure below shows a reversible heat engine ER having heat

Figure below shows a reversible heat engine ER having heat interactions with three constant temperature systems. Calculate the thermal efficiency of the heat engine

Q₁ + Q₂ - Q₃ = W .... (i)

	Q₁	+	Q₂	-	Q₃	= 0 ...... (ii)
	1000		500		300

From equation (ii) , we have

	Q₁	+	Q₂	-	Q₃	= 0
	1000		500		300

⇒ Q₃ = 60 kJ
W ⇒ 100 + 50 - 60 = 90 kJ

η =	W	=	90	= 60%
	Q₁ + Q₂		150