Ratio of the present age of a mother to that of the daughter is 7 : 1. After 5 years the ratio will become 4 : 1. What is the difference (in years) in their present ages?

30

ATQ,

Lets assume, present age of mother is 7x and daughter is x

Given, after 5 years ratio of their ages ⇒ \(\frac{7x + 5}{x + 5}\) = \(\frac{4}{1}\)

                                                        ⇒ 7x +5 = 4x + 20

                                                        ⇒ x = 5

Mother's present age = 35

Daughter's present age = 5

Difference in their present ages = 35 - 5 = 30 years