Multiple choice

The age of father 3 years ago was 2.5 times of his sons age and after 7 years it will be twice theme of his son, the present age of the father and son will be _____.

  1. 53,20

  2. 53,23

  3. 50,20

  4. 52,22
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let F and S be current ages. (F-3) = 2.5(S-3) and (F+7) = 2(S+7). Solving: F-3 = 2.5S-7.5 => F = 2.5S-4.5. Substitute: 2.5S-4.5+7 = 2S+14 => 0.5S = 11.5 => S=23. Then F = 2.5(23)-4.5 = 57.5-4.5 = 53.

AI explanation

Let the father's present age be F years and the son's present age be S years. Three years ago, the equation was F minus 3 equals 2.5 times S minus 3, which simplifies to 2F equals 5S minus 9. Seven years from now, the equation is F plus 7 equals 2 times S plus 7, simplifying to F equals 2S plus 7. Substituting the second equation into the first gives 2 times 2S plus 7 equals 5S minus 9, which solves to S equals 23. Substituting S back gives F equals 2 times 23 plus 7, making the father's age 53.

Keep practicing — related questions