At the beginning of the compression process of an air standard dual cycle with a compression ratio

Question:

At the beginning of the compression process of an air standard dual cycle with a compression ratio of 18, p = 100 kPa and T = 300 K. The pressure ratio for the constant volume part of the heating process is 1.5 and the volume ratio of the constant pressure part is 1.2. Determine
(a) The thermal efficiency and
(b) The MEP. Use the PG model.