Mathematics

A hollow sphere has a volume of kcm3 and a surface area of kcm2. Calculate…

A hollow sphere has a volume of kcm3 and a surface area of kcm2. Calculate the diameter of the sphere.

  • A.
    3cm
  • B.
    6cm
  • C.
    9cm
  • D.
    12cm
  • E.
    More information is needed
Correct Answer: Option B
Explanation

(Volume = frac{4}{3} pi r^3 = k) …(i)

(S.A = 4pi r^2 = k) … (ii)

Divide (i) by (ii),

(frac{4}{3} pi r^3 div 4pi r^2 = frac{k}{k})

(frac{r}{3} = 1 implies r = 3cm)

Diameter = 2 x 3cm = 6cm