Who can help me solve this problem?

One mole of an ideal monatomic gas at STP first undergoes an isothermal expansion so that the volume at point b is 2.5times the volume of point a. Next, the heat is extracted at a constant volume so that the pressure drops. The gas is then compressed adiabatically back to the original state.

Question a:

Calcultate the pressures at point b and point c

Question b:

Determine the temperature at point c

Question c:

Determine the work done, heat input or extracted, and the change in entropy for each process.

Question d:

What is the efficiency of this cycle>?

Question e:

WHat is the change in entropy 'delta s' for one complete cycle a->b->c->a? Explain your reasoning

Question f:

In which part of the cycle does the entropy, S, show the greatest decrease? Explain your reasoning

Many thanxxx