Question

Two satellites S and S' revolve around the earth at distances 3R and 12R frm d centre of the earth.
The periods of revolution of S and S' are in the ratio of......
1)1:2
2)2:1
3)8:1
4)1:8

Answer 1

T1^2/T2^2=R1^3/R2^3

                 =(3R)^3/(12R)^3

                 =3*3*3/12*12*12

                 =1/64

T1/T2         =1/8

I.e,           1:8

hope you understand, thank you