A gaseous mixture contains $56\;g$ of $N_2,44\;g$ of $\; CO_2$ and $16\; g$ of $CH_4$. The total pressure of the mixture is $720 \;mm$ Hg. The partial pressure of $CH_4$ is :

Question

$$\begin {array} {1 1} (a)\;180\;mm & \quad  (b)\;360\;mm \\  (c)\;540\;mm & \quad (d)\;720\;mm \end {array}$$