b$)$ The volume of a gas increases from $3L$ to $9L$ at a constant pressure of $4$atm. Next, heat i

added to increase the pressure to $10$atm at constant volume. Finally, heat is removed to

decrease the pressure and volume to its original values in a straight$-$line path. $($i$)$ Draw

$P-V$ diagram for the entire process. $($ii$)$ Calculate the total work done in the process in

units.