Difficulty: Easy
Correct Answer: 5 : 6 : 7
Explanation:
Introduction / Context:
When a ratio and total are given, compute the common unit, obtain actual present ages, then add the future increment to each and reduce to the simplest ratio for the future time.
Given Data / Assumptions:
Concept / Approach:
The sum of ratio parts is 3 + 4 + 5 = 12. One unit equals 48 / 12 = 4. Present ages are 12, 16, and 20. Add 8 to each and reduce.
Step-by-Step Solution:
1) Present ages: 3×4 = 12; 4×4 = 16; 5×4 = 20.2) After 8 years: 20, 24, 28.3) Simplify 20 : 24 : 28 by dividing by 4 ⇒ 5 : 6 : 7.
Verification / Alternative check:
All three increased equally by 8, so internal differences remain consistent; the simplified ratio is correct.
Why Other Options Are Wrong:
Common Pitfalls:
Forgetting to simplify the final ratio or incorrectly applying the total to find the unit are common issues.
Final Answer:
5 : 6 : 7
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