In a thermodynamic cycle, an isobaric process is one where the pressure ($P$) remains constant. The work done by the gas during this process is equal to the area under the isobaric path on a P-V diagram and is calculated using the formula $W = P\Delta V = P(V_f - V_i)$. Since the required P-V diagram is missing from the question text, the exact initial and final volumes, as well as the constant pressure, cannot be determined. Assuming the probable answer provided is derived from the missing figure, the work done evaluates to 600 J.