In two separate experiments, a sample of helium gas is taken from the same initial state to the same final state, along two separates paths on a P-V diagram. Path a has two parts: first an isochor and second isobar. Path b is an isotherm. Determine the work done by the gas (i) along path a (ii) along path b. The pressure and volume at the initial and final state are Pi=200 KPa, Vi =42 L, Pf =90 KPa and Vf =100L.