Difficulty: Medium
Correct Answer: If neither Conclusion I nor II follows
Explanation:
Introduction / Context:From a single trend—household electricity consumption has doubled over five years—we must judge whether two broad conclusions are logically necessary: that society has developed a lot, or that electricity has become cheaper.
Given Data / Assumptions:
Concept / Approach:Logical necessity requires that a conclusion hold in every scenario consistent with the given statement. We therefore test whether each conclusion must be true across plausible explanations for higher usage.
Step-by-Step Solution:
1) Test Conclusion I (development): Consumption might increase due to wastefulness, heat waves, larger households, or inefficient devices—not necessarily “development.” Conversely, development could also increase usage, but it is not the only explanation. Hence I is not compelled.2) Test Conclusion II (cheaper power): Usage could rise even if power becomes more expensive (e.g., mandatory electrification of cooking, new devices). Without tariff data, II is not forced.Verification / Alternative check:Construct scenarios: (a) Tariffs increased, but appliance additions led to higher usage; (b) Tariffs decreased, leading to more usage; (c) No tariff change, but climate/remote work increased consumption. The statement holds in all three—therefore neither conclusion is necessary.
Why Other Options Are Wrong:
• Any option asserting I or II assumes unstated causal links.• “Both” is doubly unsupported.Common Pitfalls:Confusing correlation (higher usage) with causation (development or cheaper rates); assuming a single cause when multiple factors can explain the observation.
Final Answer:Neither Conclusion I nor II follows.
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