Difficulty: Easy
Correct Answer: 8 : 5
Explanation:
Introduction / Context:Given a ratio and a product, we find the common multiplier by taking the square root after factoring properly. Once current ages are known, adding 6 to both yields the future ratio.
Given Data / Assumptions:
Concept / Approach:Let ages be 7x and 4x. Then 28x^2 = 1008 gives x. Compute current ages, add 6 to both, and simplify the ratio.
Step-by-Step Solution:
7x * 4x = 28x^2 = 1008 ⇒ x^2 = 36 ⇒ x = 6Father now = 42, Son now = 24After 6 years ⇒ 48 : 30 = 8 : 5Verification / Alternative check:Product check: 42 * 24 = 1008; ratio update is correct after equal increments of 6 years.
Why Other Options Are Wrong:5 : 3 and 7 : 4 are not the future ratio; 5 : 8 reverses the order and is incorrect.
Common Pitfalls:Forgetting that adding the same years to both changes the ratio unless both ages are equal initially.
Final Answer:8 : 5
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