Question

The dimeter of two silver discs are in the ratio 2:3 what will be the ratio of their areas ?

Answer 1

hope this will be heplful....
regards
Cheshta

Answer 2

ratio of diameters of 2 discs = 2:3 = 2d/3d
so , ratio of radius will be the same ,
as , (2d/2)/(3d/2) = 2:3 = 2r:3r
ar of small disc = pi (2r)^2r
ar of larger disc = pi (3r)^2r
ratio of area = pi 4r^2 ÷ pi 9r^2
so ratio is 4:9
hope so answer is correct