An ideal Stirling engine using helium as the working fluid operates between the temperature limits of 300

Question:

An ideal Stirling engine using helium as the working fluid operates between the temperature limits of 300 K and 1800 K and pressure limits of 150 kPa and 1200 kPa. Assuming the mass used in the cycle is 1.5 kg, determine
(a) The thermal efficiency (ηth) of the cycle,
(b) The amount of heat transfer in the regenerator, and
(c) The work output per cycle.