Difficulty: Easy
Correct Answer: 42, 14
Explanation:
Introduction / Context:We combine a current multiplicative relation with a future sum. This yields a single linear equation in one variable (the son’s age), which can be solved directly and then scaled to get the father’s age.
Given Data / Assumptions:
Concept / Approach:Form the linear equation from the future sum and solve for x, then compute 3x. Age constraints (positive integers) are naturally met by the solution here.
Step-by-Step Solution:
4x + 20 = 76 ⇒ 4x = 56 ⇒ x = 14Father = 3x = 42Verification / Alternative check:In 10 years: son 24, father 52; 24 + 52 = 76 as required.
Why Other Options Are Wrong:39,13 or 45,15 do not satisfy the future-sum constraint when paired with the 3x relation.
Common Pitfalls:Adding 10 to only one person or mistaking “three times” for “three more than”.
Final Answer:42, 14
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