Question

The diameter of the moon is approximately one fourth of the diameter of the earth.Find the ratio of their surface areas

Answer 1

2r of moon=1/42rofearth
r moon= 1/4earth
surface area=4pie r^2
ratio=1:16

Answer 2

hi, my friend here is Ur answer.
let the diameter of earth be X
then diameter of moon is 1/4of X according to question
now, radius of earth is X/2
and radius of moon =X/4÷2
so, radius of moon =X/8
formula of surface area =4πrsquare
so, surface area of earth=4×π×(X/2) whole Square.=4×π×xsquare/ 4=π×Xsquare
Again surface area of moon=4×π×(x/8) whole Square.=4×π×xsquare/64=π×xsquare/16
their ratio is=π×xsquare/18÷π×xsquare
=1/16
so, the ratio of moon and earth is1:16