Consider two solid sphere P and Q each of density $8 \mathrm{gm} \mathrm{cm}^{-3}$ and diameters 1 cm and 0.5 cm , respectively. Sphere $P$ is dropped into a liquid of density $0.8 \mathrm{gm} \mathrm{cm}^{-3}$ and viscosity $\eta=3$ poiseulles. Sphere $Q$ is dropped into a liquid of density $1.6 \mathrm{gm} \mathrm{cm}^{-3}$ and viscosity $\eta=2$ poiseulles. The ratio of the terminal velocities of $P$ and $Q$ is