Alligation–Mixture (Combining Three Bottles): Three equal-capacity bottles contain milk:water in ratios 2:5, 3:4, and 4:5. After pouring all into a larger bottle, what is the overall ratio of milk to water?
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A73 : 106
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B73 : 116
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C73 : 113
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D73 : 189
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ENone of these
Answer
Correct Answer: 73 : 116
Explanation
Introduction / Context:When combining mixtures with equal capacities, add component fractions directly.
Given Data / Assumptions:
- Each bottle has capacity 1 unit (for convenience).
- Ratios: 2:5 ⇒ milk 2/7; 3:4 ⇒ milk 3/7; 4:5 ⇒ milk 4/9.
Concept / Approach:Total milk = 2/7 + 3/7 + 4/9. Total volume = 3 units; so total water = 3 − total milk. Convert to a common denominator to sum exactly.
Step-by-Step Solution:1) Milk = 2/7 + 3/7 + 4/9 = 5/7 + 4/9 = 45/63 + 28/63 = 73/63.2) Water = 3 − 73/63 = 189/63 − 73/63 = 116/63.3) Ratio milk:water = (73/63) : (116/63) = 73 : 116.
Verification / Alternative check:Proportional reasoning with equal capacities preserves the ratio calculation.
Why Other Options Are Wrong:Other denominators do not match the exact fractional sums.
Common Pitfalls:Averaging ratios directly (invalid); ignoring unequal denominators 7 and 9.
Final Answer:73 : 116