Net work and efficiency of a cycle

A monatomic gas goes clockwise round a rectangle: up at $1.2\ \text{L}$ from $1.2 \times 10^{5}\ \text{Pa}$ to $3.5 \times 10^{5}\ \text{Pa}$, out to $3.2\ \text{L}$, down, and back. You will make the program find the net work, the heat taken in, and the efficiency of an engine using this cycle.

The idea. The net work is the area of the loop. Heat goes in on the two steps where the gas warms: A to B at a steady volume, $Q = \tfrac32 V\,\Delta p$, and B to C at a steady pressure, $Q = \tfrac52 p\,\Delta V$. The efficiency is $\dfrac{W}{Q_\text{in}}$.

Your tasks.

1. Work out the net work W.
2. Work out Q_AB, Q_BC and the total heat taken in, Q_in.
3. Work out the efficiency eff.