A plano-convex lens having radius of curvature of first surface 2 cm exhibits focal length of f_1 in air. Another plano-convex lens with first…

A plano-convex lens having radius of curvature of first surface $\displaystyle 2$ cm exhibits focal length of $\displaystyle f_1$ in air. Another plano-convex lens with first surface radius of curvature $\displaystyle 3$ cm has focal length of $\displaystyle f_2$ when it is immersed in a liquid of refractive index $\displaystyle 1.2$ . If both the lenses are made of same glass of refractive index $\displaystyle 1.5$ , the ratio of $\displaystyle f_1$ and $\displaystyle f_2$ will be