An ideal gas is subjected to a cyclic process involving four thermodynamic states; the amounts of heat (Q) and work (W) involved in each of these states areQ1 = 6000 J, Q2 = – 5500 J ;  Q3 = – 3000 J; Q4 = 3500 JW1 = 2500 J; W2 = – 1000 J; W3 = – 1200 J; W4 = xJ.The ratio of the net work done by the gas to the total heat abosrbed by the gas is 'η'. The values of x and 'η' respetively are