Multiple choice

6 years ago, the ages (in years) of A and B were in the ratio (4 : 5) and 6 years hence they will be in the ratio (5 : 6). The present age of B is.

  1. 48 years

  2. 34 years

  3. 72 years

  4. 66 years

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

6 years ago: A=4x, B=5x. Present: A=4x+6, B=5x+6. 6 years hence: (4x+12)/(5x+12) = 5/6. Cross-multiply: 24x+72 = 25x+60, giving x=12. B's present age = 5(12)+6 = 66 years. Option A (48) would require x=8.4, which doesn't satisfy the second ratio condition.