A hallow sphere has a volume of kcm^3 and a surface area of kcm^2.what is the value of the diameter of the sphere if it is tripled
Why not just say: the volume equals the surface area
(4/3)πr^3 = 4πr^2
times 3/π
4r^3 - 12r^2 = 0
r^3 - 4r^2 = 0
r^2(r - 4) = 0
r = 0 (trivial solution)
or
r = 4 or the diameter is 8
Your actual question is strangely worded.