The total surface area of a solid is and its curved surface area is of the total surface area. Find the volume of the cylinder.
Given,
Total surface area of solid = 231 cm2
2πr(h + r) = 231
⇒ r (r + h) =
⇒ r2 + rh =
CSA =
2πrh =
⇒ rh =
Putting value of rh in (i) we get,
⇒ r2 +
⇒ r2 =
⇒ r =
From equation (ii)
⇒ rh =
⇒ h =
∴ Volume of cylinder = πr2h = × 3.5 × 3.5 × 7 = 269.5 cm3