Multiple choice

Age of A and B are presently in the ratio of 5 : 6 respectively. Six years hence this ratio will become 6 : 7 respectively. What was B's age 5 years ago?

  1. 25 years

  2. 30 years

  3. 36 years

  4. 31 years

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

Let present ages be 5x and 6x. Six years later: (5x+6)/(6x+6) = 6/7. Solving: 7(5x+6) = 6(6x+6), so 35x+42 = 36x+36, giving x = 6. Present ages are 30 and 36. Five years ago, B was 36 - 5 = 31 years.