In each of the following figures, find the ratio of the shaded region to the unshaded region.

(a) Number of shaded parts = 4
Number of unshaded parts = 12
∴ Ratio = 4 : 12 = 4/12 = (4 ÷ 4)/(12 ÷ 4) = 1/3
Required ratio = 1 : 3

(b) Number of shaded parts = 2
Number of unshaded parts = 4
∴ Ratio = 2 : 4 = 2/4 = (2 ÷ 2)/(4 ÷ 2) = 1/2
Required ratio = 1 : 2