The average age of husband and his wife was 23 years at the time of their marriage. After five tears they have a one-year old child. The average age of the family of three, when the child was born, was-

Answer: Option C

According to the question,
$$\frac{H+W}{2}$$   = 23 years
H + W = 46 years.....(i)
As given in the question after five years they have a one-year old child.
i.e., After 4 years of marriage child was born
∴ Average of (H + E + C)
= $$\frac{46+8}{3}$$
= $$\frac{54}{3}$$
= 18 years