If the ratio of volumes of two spheres is 1:8, then the ratio of their surface  area is 1:2        (b)  1:4     (c)  1:8        (d)  1:16

Explanation

given ration of their volume is `1:8`
`4/3pir1^3:4/3pir2^3h=1:8`
`r1^3:r2^3=1:8`
`r1:r2=1:8`
Surface area of a sphere of radius `r=4pir^2`
Now, ratio of their surface areas is`=s1:s2`
`4pir1^2:4pir2^2h`
`r1^2:r2^2`
`1^2:2^2=1:4`