Going from i to f in each of the three proce sses of f 1.1, is work done by the system (w0, w 0), is wor the system ( w> 0, w. 0), or is no net work done? b) c)

now see figure a, volume at i is less than volume at f so automatically work done is positive and work is done by the system..for any doubt I can ask.

look figure b, pressure and volume at i is greater than pressure and volume at f ( see easily from figure,no need of the values of v, p) so the work done is change in volume*press...

look figure c, there is no change in volume when system go from i to f that means no work done as work done=pressure*change in volume