A piston/cylinder device operating in a cycle with steam as the working fluid executes the following steps:

Question:

A piston/cylinder device operating in a cycle with steam as the working fluid executes the following steps:
• Saturated-vapor steam at 300(psia) is heated at constant pressure to 900(oF).
• It then expands, reversibly and adiabatically, to the initial temperature of 417.35(oF).
• Finally, the steam is compressed in a mechanically reversible, isothermal process to the initial state.
What is the thermal efficiency of the cycle?