Average age of couple at the time of marriage is 28 years. In interval of 5 years of the marriage they had one girl A and in interval of 8 years of the marriage they had another girl B. If the average age of the family after 8 years of marriage is 18.75, find the age of the girl A.
1
6 years
2
12 years
3
4 years
4
16 years
5
3 years