Problems on Ages — “Five years ago, Ashok’s mother was 3 times his age. Five years from now, she will be twice his age. Find Ashok’s present age.”

Difficulty: Medium

Correct Answer: 15 years

Explanation:


Introduction / Context:
Here we have two time-shifted multiplicative relations between the same two people. Represent the present ages with variables and translate each statement into an equation at the appropriate time point; solving the system gives Ashok’s current age.


Given Data / Assumptions:

  • Let Ashok = x, Mother = y (present ages).
  • Five years ago: y − 5 = 3(x − 5).
  • Five years hence: y + 5 = 2(x + 5).


Concept / Approach:
Convert both conditions to present-age equations and solve simultaneously.


Step-by-Step Solution:

From past: y − 5 = 3x − 15 ⇒ y = 3x − 10. …(1)From future: y + 5 = 2x + 10 ⇒ y = 2x + 5. …(2)Equate (1) and (2): 3x − 10 = 2x + 5 ⇒ x = 15.Therefore Ashok’s present age = 15 years.


Verification / Alternative check:
Five years ago: Ashok 10, Mother from (1) ⇒ y = 35 ⇒ 35 = 3 * 10 + 5? Actually condition is y − 5 = 3(x − 5) ⇒ 30 = 3 * 10 ✓; Five years hence: Ashok 20, Mother 40 ⇒ 40 = 2 * 20 ✓.


Why Other Options Are Wrong:
10/20/25/18 break one of the time-shifted multiplicative conditions when checked in both directions.


Common Pitfalls:
Applying the multiplier to present ages (3x) instead of to the shifted age (x − 5); forgetting to add/subtract 5 to both ages for the same time frame.


Final Answer:
15 years

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