Multiple choice

The present ages of a father and his son are in the ratio 6 : 1. Four years from now, the ratio of their ages will be 4 : 1. What is the son's present age?

  1. 10 years

  2. 6 years

  3. 4 years

  4. 8 years

  5. None of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let the present ages of the father and son be 6x and x, respectively. In four years, their ages will be 6x + 4 and x + 4, and their ratio is 4 : 1. Solving the equation (6x + 4) / (x + 4) = 4 gives x = 6, which represents the son's present age.

AI explanation

Let the present ages of the father and son be 6x and x respectively. In 4 years, their ages will be 6x + 4 and x + 4, giving the equation (6x + 4) / (x + 4) = 4 / 1. Solving yields 6x + 4 = 4x + 16, which simplifies to 2x = 12 and x = 6. The son's present age is x, which is 6 years.