Tests on an adiabatic gas turbine (expander) yield values for inlet conditions (1, P} and outlet conditions

Question:

Tests on an adiabatic gas turbine (expander) yield values for inlet conditions (1\, P\} and outlet conditions (73. P2). Assuming ideal gases with constant heat capacities, determine the turbine efficiency for one of the following:
(a) T1 = 500 K. P1 = 6 bar. T2 = 371 K, P2 = 1.2 bar. CP/R = 7/2
(b) T1 = 450 K. P1 = 5 bar. T2 = 376 K. P2 = 2 bar. CP/R = 4.
(c) T1 = 525 K. P1 = 10 bar. T2 = 458 K. P2 = 3 bar. CP/R = 11/2.
(d) T1 = 475 K. P1 = 7 bar. T2 = 372 K. P2 = 1.5 bar. CP/R = 9/2,
(e) T1 = 550 K. P1 = 4 bar. T2 = 403 K. P2 = 1-2 bar. CP/R = 5/2.