Ages of a mother and daughter are in the ratio 9 : 2. The daughter was born when the mother was 28 years. How old is the daughter?

Correct option is C

Given:
Age ratio = 9:2.
The mother was 28 years old when the daughter was born.
Solution:
Let the daughter’s age be x years.
Mother’s age = 28 + x.
Since the ratio of their ages is 9:2:
​$$\frac{(28 + x)}{x }= \frac92.$$​​
2(28 + x) = 9x.
56 + 2x = 9x.
56 = 7x

→ x = 8.