Problems on Ages — “Surabhi : Neerja = 6 : 7 at present. After 6 years the ratio becomes 15 : 17. Find Neerja’s present age.”

Difficulty: Easy

Correct Answer: 28 years

Explanation:

Introduction / Context:When a present-time ratio and a future ratio are given, express present ages using a common multiplier, then apply the future condition to determine that multiplier.

Given Data / Assumptions:

  • Now: Surabhi : Neerja = 6 : 7 ⇒ S = 6x, N = 7x.
  • After 6 years: (S + 6) : (N + 6) = 15 : 17.

Concept / Approach:Set up a proportion with the unknown x and solve by cross-multiplication. Integers are expected for typical age problems.

Step-by-Step Solution:

(6x + 6)/(7x + 6) = 15/17.17(6x + 6) = 15(7x + 6) ⇒ 102x + 102 = 105x + 90.Rearrange: 12 = 3x ⇒ x = 4.Neerja N = 7x = 28 years.

Verification / Alternative check:Now (24, 28) → after 6 years (30, 34) = 15:17 ✓.

Why Other Options Are Wrong:24/26/30/32 years break the 15:17 future ratio when paired with S = 6x.

Common Pitfalls:Using the same multiplier for future ages instead of adding years; or incorrectly simplifying the ratio before substitution.

Final Answer:28 years

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