Difficulty: Medium
Correct Answer: 38 : 11
Explanation:
Introduction / Context:
We are given two timed conditions to pin down two unknown present ages, then asked for their ratio. As usual, convert each sentence into an equation in present-day variables.
Given Data / Assumptions:
Concept / Approach:
Solve the system. From the first, M = 4S − 6. Substitute into the second to find S, then M, and finally reduce M : S.
Step-by-Step Solution:
1) Substitute: (4S − 6) + 6 = 2S + 22 ⇒ 4S = 2S + 22.2) 2S = 22 ⇒ S = 11.3) M = 4S − 6 = 44 − 6 = 38.4) Ratio M : S = 38 : 11.
Verification / Alternative check:
Two years ago: 36 vs 9 → 36 = 4 × 9. In six years: 44 vs 17 → 44 = 2 × 17 + 10, OK.
Why Other Options Are Wrong:
They do not match both time-shifted conditions simultaneously.
Common Pitfalls:
Dropping the +10 in the future condition or mishandling the −2 on both sides in the past condition.
Final Answer:
38 : 11
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