In the first stage of a two-stage Carnot engine, energy is absorbed as heat Q1 at temperature T1 = 530 K, work W1 is done, and energy is expelled as heat Q2 at a lower temperature T2 = 410 K. The second stage absorbs that energy as heat Q2, does work W2, and expels energy as heat Q3 at a still lower temperature T3 = 200 K. What is the efficiency of the engine?