Multiple choice

A father's age is four times his son's present age. After 18 years, the father's age will be twice his son's age. The father's and son's present ages respectively are

  1. 9 and 36 years

  2. 40 and 10 years

  3. 32 and 8 years

  4. 36 and 9 years

  5. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let F=4S. (F+18) = 2(S+18). 4S+18 = 2S+36, so 2S=18, S=9. F=4*9=36.

AI explanation

Let the son's present age be S years, making the father's age 4S years. Using the future age condition gives the equation 4S + 18 = 2 times (S + 18). Solving yields 4S + 18 = 2S + 36, which simplifies to 2S = 18 and S = 9. The father's present age is 4 times 9, or 36 years, making their respective ages 36 and 9 years.

Keep practicing — related questions