Final answer:
The probability that a couple will have two girls and one boy out of three children is 3/8 or 0.375.
Step-by-step explanation:
To find the probability that a couple will have two girls and one boy out of three children, we can use the concept of probability and combinations. The total number of possible outcomes for three children is 2^3 = 8, since each child can be either a girl or a boy. Out of these 8 possible outcomes, there are three outcomes where two children are girls and one is a boy: GGB, GBG, and BGG. Therefore, the probability that a couple will have two girls and one boy is 3/8 or 0.375.