Question

In a European country, 20% of the families have three children, 30% have two children,
40% have one child, and 10% have no children. On average, how many children are there to a
family

Answer 1

Let number of families be x

No. of children in with 3 = 20%x X 3 = 0.6x
No. of children in with 2 = 30%x X 2 = 0.6x
No. of children in with 1 = 40%x X 1 = 0.4x
No. of children in with 0 = 10%x X 0 = 0

Average per house = (.6x + .6x + .4x)/x
=1.6x/x
=1.6