Multiple choice

The respective ratio between the present age of A, B, C and D is 2 : 7 : 8 : 12. The average age of A and B is 27 years. What will be B's age after 7 years?

  1. 40 years

  2. 41 years

  3. 48 years

  4. 49 years
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let ages be 2k, 7k, 8k, 12k. Average of A and B: (2k+7k)/2 = 4.5k = 27, so k = 6. B's current age = 7 × 6 = 42. After 7 years: 42 + 7 = 49. The ratio determines relative ages; average gives the scale factor.

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