' x ' g of molecular oxygen O 2 is mixed with 200   g of neon Ne . The total pressure of the…

'$\mathrm{x}$' $\mathrm{g}$ of molecular oxygen $\left({\mathrm{O}}_2\right)$ is mixed with $200 \mathrm{g}$ of neon $\left(\mathrm{Ne}\right)$. The total pressure of the nonreactive mixture of ${\mathrm{O}}_2$ and $\mathrm{Ne}$ in the cylinder is $25$ bar. The partial pressure of $\mathrm{Ne}$ is $20$ bar at the same temperature and volume. The value of '$\mathrm{x}$' is

[Given: Molar mass of ${\mathrm{O}}_2=32 \mathrm{g} {\mathrm{mol}}^{-1}$. Molar mass of $\mathrm{Ne}=20 \mathrm{g} {\mathrm{mol}}^{-1}$]