Classification – Ordered pairs (ratio rule): identify the odd one out. In three pairs the ratio y:x equals 8:7 exactly; one pair does not satisfy this exact ratio. Which pair is different? Options: 21 : 24, 28 : 32, 14 : 16, 54 : 62.
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A21 : 24
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B28 : 32
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C14 : 16
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D54 : 62
Answer
Correct Answer: 54 : 62
Explanation
Introduction / Context:Pair classifications can also use a fixed proportionality. Here the first three look like they preserve y:x = 8:7. We verify and find the outlier.
Given Data / Assumptions:
- Check whether y = (8/7) * x.
- Pairs: (21,24), (28,32), (14,16), (54,62).
Concept / Approach:Compute 8/7 of each x and compare with y. Exact equality (not rounding) is required.
Step-by-Step Solution:x=21 → (8/7)*21=24 → matches.x=28 → (8/7)*28=32 → matches.x=14 → (8/7)*14=16 → matches.x=54 → (8/7)*54=432/7=61.714… ≠ 62 → mismatch.
Verification / Alternative check:Reduce each pair to lowest terms: 24:21=8:7, 32:28=8:7, 16:14=8:7, whereas 62:54 simplifies to 31:27, not 8:7.
Why Other Options Are Wrong:21:24, 28:32, 14:16: Each preserves the exact 8:7 ratio.
Common Pitfalls:Accepting near-equality by rounding; this task requires exact proportionality.
Final Answer:54 : 62