From a circular sheet of paper with a radius 20 cm, four circles of radius 5 cm each are cut out

From a circular sheet of paper with a radius 20 cm, four circles of radius 5 cm each are cut out. What is the ratio of the uncut to the cut portion?

  1. 4 : 3
  2. 4 : 1
  3. 3 : 1
  4. 1 : 3

Answer

Four circles of radius 5 cm are cut out.

Area cut = 4*(π52) = 100π

Total area of circular sheet = π(20)2 = 400π

Area uncut = 300π

The ratio of uncut to cut portion is 3 : 1

The correct option is C.