The average of a couple was 24 years when the child was just born what will be the age of the father when child reaches to the age of the mother when she gave him the birth

With the given information we can only assume that the mother was 24 when they had a child because there's no information on if the mother or father is older or anything like that so therefore the father would be 24 when the child is born as well, making the father 48 when the child reaches 24.

If you divide 0.1 and 0.6 you wii get 0.166666 which rounds to .167 which is answer b