Question

1. In a family of 4 children, the probability of a male birth is 0.5. Find the probability that the family has (a) at least 1 boy. (b) equal number of each gender

Answer 1

(a) P(at least 1 boy) = 1 - (1/2)⁴

= 1 - 1/16 = 15/16

(b) 4!/(2!2!) = 24/(2(2)) = 24/4 = 6

P(2 girls, 2 boys) = 6(1/2)⁴ = 6(1/16)

= 3/8