A couple has three children. Assuming each child has an equal chance of being a boy or a girl, what is the probability that they have at least one girl?
A) .125
B) .5
C) .875
D) 1

Question

Quizplus · Accepted Answer

There are 8 possible gender combinations for three children: BBB, BBG, BGB, BGG, GBB, GBG, GGB, and GGG. Only one out of these 8 combinations does not have a girl, so the probability of having at least one girl is: 
P(at least one girl) = 1 - P(no girls) 
P(no girls) = 1/8 
P(at least one girl) = 1 - 1/8 = 7/8 = 0.875

A Couple Has Three Children