In the given figure container A holds an ideal gas at a pressure of $ 50\times 10^{5}\, Pa$ and a temperature of $300 \,K$. It is connected by a thin tube (and a closed) container $B$, with four times the volume of $A$. Container $B$ holds same at a pressure of $ 1.0\times 10^{5} \, Pa$ and a temperature of $400 \,K$. The valve is open allow the pressures to equalize, but the temperature of each container constant at its initial value. The final pressure in the two containers will be to