Gọi a, 2a, 2a là thể tích mỗi khí
\(\Rightarrow a+2a+2a=11,2\)
\(\Rightarrow a=2,24\)
\(\Rightarrow V_{CH4}=2,24\left(l\right);V_{O2}=4,48\left(l\right)\)
\(\Rightarrow\left\{{}\begin{matrix}\%_{CH4}=\frac{2,24.100}{11,2}=20\%\\\%_{O2}=\%_{CO2}=40\%\end{matrix}\right.\)