Question

Newlyweds Katherine and Matthias plan to have two children. Assuming it is equally likely to be a boy or a girl, use the tree diagram to help you find the probability that their second child is a girl, given that their first child is a boy.

Reference Media Image
Select an answer

A.
1/8


B.
1/4


C.
1/2


D.
3/4

Answer 1

If the first child is a boy, the possible equally likely outcomes for the two children are BB and BG. Only BG has a girl as the second child, so the probability is 1/2.

Answer: C.