Question

The diameter of moon is approximately 1/4th of the diameter of earth . Find the ratio of their surface areas

Answer 1

4(Diameter of moon) = Diameter of earth

Diameter of moon will be lesser than that of earth

Therefore,
 diameter of moon can be x and Diameter of earth can be 4x

S.A of moon = $\pi x^{2}$
S.A of  earth = $\pi (4x)^{2}$

 S.A of moon : S.A of earth = $\pi x^{2}$ : $\pi (4x)^{2}$
                                               =  1 : 16

Therefore, the ratio of S.A of moon : Earth = 1 :16