The ratio of a father’s age to his son’s age is 4 : 1, and the product of their ages is 196. What will be the ratio of their ages after 5 years?

Difficulty: Easy

Correct Answer: 11 : 4

Explanation:

Introduction / Context:Classic age problems often provide a ratio and the product (or sum). Use the ratio to write ages in terms of a variable, solve from the product, and then apply the time shift to compute the new ratio.

Given Data / Assumptions:

  • Father : Son = 4 : 1 ⇒ ages = 4x and x.
  • Product = 196 ⇒ 4x^2 = 196.
  • We seek (4x + 5) : (x + 5).

Concept / Approach:Solve x from the product, then add 5 years to each age and simplify the resulting ratio.

Step-by-Step Solution:

4x^2 = 196 ⇒ x^2 = 49 ⇒ x = 7 (ages positive).Father = 28, Son = 7.After 5 years: 33 and 12 ⇒ ratio = 33 : 12 = 11 : 4.

Verification / Alternative check:Product check: 28×7 = 196; post-increment ratio simplifies correctly.

Why Other Options Are Wrong:3:1, 10:3, or 14:5 do not match the computed post-increment ages.

Common Pitfalls:Using 196 as the sum instead of product, or forgetting to simplify the final ratio.

Final Answer:11 : 4

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