Two containers hold ideal gases at the same temperature. Container A has twice the volume and half the number of particles as container B. What is the ratio $P_{\mathrm{A}} / P_{\mathrm{B}}$, where $P_{\mathrm{A}}$ is the pressure in container $\mathrm{A}$ and $P_{\mathrm{B}}$ is the pressure in container $B$ ?