The equilibrium constants $K_{P1}$ and $K_{P2}$ for the reactions $\mathrm{X \rightleftharpoons 2Y}$ and $\mathrm{Z \rightleftharpoons P + Q}$, respectively are in the ratio of 1 : 9. If the degree of dissociation of X and Z be equal then the ratio of total pressure at these equilibria is: