Question
A sphere has a radius of 8 cm. A solid cylinder has a
base radius of 4 cm and a height of h cm. If the total surface area of the cylinder is half the surface area of the sphere, then find the height of the cylinder.Solution
According to the question- The total surface area of the cylinder is half the surface area of the sphere. Â 2
(h + r) / 4
  r2= 1/2 = 2 x π × 4(h + 4)/ (4 × π × 82) = 1/2  8(h + 4) / 256 = 1/2  h + 4/32 = ½  h + 4 = 16 h = (16 - 4) h  = 12cm  The height of the cylinder is 12 cm.
More Previous year papers Questions