Alligation–Mixture (Two Acid–Water Solutions): Two bottles have acid:water ratios 2:3 and 1:2, respectively. Mixed in the ratio 1:3 (by volume), what is the final acid:water ratio?
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A7:13
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B11:57
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C23:37
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D1:3
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ENone of these
Answer
Correct Answer: 7:13
Explanation
Introduction / Context:Combining solutions requires adding absolute component amounts, not averaging ratios.
Given Data / Assumptions:
- Bottle A (2:3), Bottle B (1:2).
- Volumes mixed A:B = 1:3.
Concept / Approach:Let A = 1 unit, B = 3 units. Compute acid and water separately, then form the ratio.
Step-by-Step Solution:1) Acid from A = 1*(2/5) = 2/5; water from A = 3/5.2) Acid from B = 3*(1/3) = 1; water from B = 3*(2/3) = 2.3) Total acid = 2/5 + 1 = 7/5; total water = 3/5 + 2 = 13/5 ⇒ ratio 7:13.
Verification / Alternative check:Divide both totals by 1/5 to see integer ratio 7:13.
Why Other Options Are Wrong:They arise from averaging ratios or mixing numeric errors.
Common Pitfalls:Taking arithmetic means of ratios—never valid for mixture composition.
Final Answer:7:13