### Average age of 6 sons of a family is 8 years. Average age of sons together with their parents is 22 years. If the father is older than the mother by 8 years, the age of mother (in years) is.

A. 44 B. 52 C. 60 D. 68 Answer: Option C
Sum of ages of 6 sons of a family = 8 × 6 = 48 Sum of ages of 6 sons and their parents = 8 × 22 = 176 $\begin{array}{l}\text{Parents’s age = 176 – 48 = 128}\\ \text{Father’s age – Mother’s age = 8}\\ \text{x – y = 8}\\ \text{x + y = 128}\\ \text{x = 68}\\ \text{y = 60}\\ \text{∴ Mother’s age = 60 years}\end{array}$