The volume of the two spheres are in the ratio 64:27. Find the difference of their surface areas, if the sum of their radii is7.

Explanation

Ratios of volumes of two spheres=`64:27`

As we know that Volume of sphere is `4/3pir^3`

let the two radii are `r` and `R`

`therefore` `r+R=7`______1

`V^'/V^('')=(4/3pir^3)/(4/3piR^3`)

`64/27=r^3/R^3`

`r/R=4/3`

`r=4/3R`

...