Given that process is isobaric ΔT=50∘C Q in isobaric process =nCpΔT=E1 ΔU in isobaric process =nCvΔT=E2 ∴E2E1=CvCP=γ Given, gas is monoatomic $\begin{aligned}
\therefore \gamma & =1+\frac{2}{\mathrm{f}} \
& =1+\frac{2}{3} \
& =\frac{5}{3}
\end{aligned}Now,asperquestion.\begin{aligned}
& \frac{5}{3}=\frac{x}{9} \
& x=15
\end{aligned}$