Multiple choice

The ratio of age of two boys is 5:6. After two years the ratio will be 7:8. The ratio if their ages after 12 years will be =

  1. $22:24$
  2. $15:16$
  3. $11:12$
  4. $17:18$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let current ages be 5x and 6x. After 2 years: (5x+2)/(6x+2) = 7/8. Cross-multiply: 8(5x+2) = 7(6x+2) → 40x + 16 = 42x + 14 → 2x = 2 → x = 1. Current ages: 5 and 6 years. After 12 years: (5+12):(6+12) = 17:18.