12 years ago, A’s mother was four times as old as A. After 14 years she will be twice as old as A. Find the present age of A.

25

Let the age of mother 12 years ago = 4R ,

Then age of A 12 years ag0 = 1R

Age of mother after 14 years =  4R + 12 + 14 =  4R + 26

Age of A  after 14 years = 1R + 26

ATQ,

⇒ \(\frac{4R\;+\;26}{1R\;+\;26}\) = \(\frac{2}{1}\)

⇒ 4R + 26 = 2R + 52

⇒ 2R = 26

⇒ 1R = 13

Age of A at present = 13 + 12 = 25 years