Question

Neeed help,
A reversible engine contains 0.20mol of ideal monatomic gas, initially at 600K and confined to 2.0L. the gas undergoes the following cycle:
Isothermal expansion to 4.0L
Isovolumic cooling to 300K
Isothermal compression to 2.0L
Isovolumic heating to 600K
a) calculate the net heat added during the cycle
b) Calculate the net work done during the cycle
c) Determine the engine's efficiency, defined as the ratio of the work done to only the heat absorbed during the cycle
Please