Two liquids of densities ${\rho _1}$ an ${\rho _2}$ (${\rho _2}$ = 2${\rho _1}$) are filled up behind a square wall of side 10 m as shown in figure. Each liquid has a height of 5 m. The ratio of the forces due to these liquids exerted on upper part MN to that at the lower part NO is (Assume that the liquids are not mixing)