NEET UG PHYSICS MCQ: THERMODYNAMICS

An ideal monoatomic gas $\mathrm{A}$ is supplied heat so as to expand without changing its temperature. In another process, starting with same state, it is supplied heat at constant pressure. In both cases a graph of work done by gas is plotted versus heat added (Q) to the gas. The ratio of slope of graphs obtained in first & second process in $\eta_1$. The same ratio obtained for ideal diatomic gas is $\eta_2$. If the ratio $\frac{\eta_1}{\eta_2}=\frac{a}{b}$. Then find $a+b$.