Multiple choice

The ratio of the ages of a father and son is 17 : 7 respectively. 6 years ago the ratio of their ages was 3 : 1 respectively. What is the father's present age?

  1. 41 years

  2. 45 years

  3. 48 years

  4. 51 years

  5. 55 years

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

Let present ages be 17x and 7x. Six years ago: (17x-6)/(7x-6) = 3/1. Cross-multiplying: 17x - 6 = 3(7x - 6) = 21x - 18. Rearranging: 21x - 17x = 18 - 6, so 4x = 12 and x = 3. Father's present age = 17 × 3 = 51 years. Option D is correct. Options A, B, C are calculation errors, E is an overestimate.