A person’s present age is one third of the age of his mother. After 12 years, his age will be one half of the age of his mother. What is present age of his mother?
Explanation: Le the present ages of son and his mother are x years and 3x years.
Then (3x + 12) = 2( x + 12) ∴ 3x + 12 = 2x + 24 ∴ x = 12 ∴ Present age of mother = 3x = 36 years