If there is an equal probability of a child being born a boy or a girl, what is the probability that a couple who have 8 children have two children of the same sex and one of the opposite sex?
Pick:
A) 1/3
B) 2/3
C) 1/4
D) 1/16
E) 3/5
No of ways of selecting a gender - 2C1   No of ways of selecting any 2 children out of 8 = 8C2   Total possible outcomes - 2^8 (each child can be either a girl or a boy)   Probability=2C1*8C2/2^8= 2*8/2*2*2*2*2*2*2*2=16/256=1/16   Ans=1/16
<result>D</result>
If there is an equal probability of a child being born a boy or a girl, what is the probability that a couple who have 8 children have two children of the same sex and one of the opposite sex?