Kindly explain this question

Solution

η_{1} = \frac{T_{1} - T_{2}}{T_{1}} η_{2} = \frac{T_{2} - T_{3}}{T_{2}} η_{3} = \frac{T_{3} - T_{4}}{T_{3}} G i v e n η_{1} = η_{2} = η_{3} 1 - \frac{T_{2}}{T_{1}} = 1 - \frac{T_{3}}{T_{2}} {T_{2}}^{2} = T_{1} T_{3} . . . . . . . . . (1) η_{2} = η_{3} 1 - \frac{T_{3}}{T_{2}} = 1 - \frac{T_{4}}{T_{3}} {T_{3}}^{2} = T_{2} T_{4} . . . . . . . . . (2) η_{3} = η_{1} 1 - \frac{T_{4}}{T_{3}} = 1 - \frac{T_{2}}{T_{1}} T_{4} T_{1} = T_{2} T_{3} T_{3} = \frac{T_{4} T_{1}}{T_{2}} . . (3) S o l v i n g 1 a n d 3 T_{2} = {({T_{1}}^{2} T_{4})}^{1 / 3} S a m e w a y T_{2} = \frac{T_{4} T_{1}}{T_{3}} . . (4) S o l v e 2 a n d 4 T_{3} = {(T_{1} {T_{4}}^{2})}^{1 / 3}