'x' g of molecular oxygen (O2) is mixed with 200 g of neon (Ne). The total pressure of the nonreactive mixture of O2 and Ne in the cylinder is 25 bar. The partial pressure of Ne is 20 bar at the same temperature and volume. The value of 'x' is_____.
[Given: Molar mass of O2 = 32 g mol-1 .
Molar mass of Ne = 20 g mol-1 ]