Equilibrium Pressures in Isothermal Gas Expansion

Consider an isolated system containing two gases, gas A and gas B, occupying the same volume. Gas A has a molar mass of 4 g/mol and gas B has a molar mass of 16 g/mol. Both gases are initially at the same temperature of 300 K. During an isothermal expansion, gas A will occupy a larger volume relative to gas B because it has a lower mass and higher average speed of molecules as described by the Maxwell-Boltzmann distribution.

If the system is allowed to expand isothermally, what can be said about the final pressure of the gases in the system after they have expanded until equilibrium is reached in a larger volume?