Question

Given equal probabilities of the birth of a boy or girl, what is the probability that a group of four siblings includes all boys? all girls? all boys or all girls? 1/8; 1/16; 3/8 1/16; 1/8; 3/8 1/16; 1/16; 1/64 1/16; 1/16; 1/8

Answer 1

The correct answer is 1/16; 1/16; and 1/8.

If there is an equal chance of having a boy or a girl, we will use 1/2 as the probability for each.

P(4 boys) = (1/2)^4 = 1/16
P(4 girls) = (1/2)^4 = 1/16
P(4 boys or 4 girls) = (1/2)^4+(1/2)^4 = 1/16+1/16 = 2/16 = 1/8