Clock angle change — What is the percentage change in the (smaller) angle between the minute and hour hands from 2:00 PM to 6:00 PM?
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A100
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B200
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C250
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DNone of these
Answer
Correct Answer: 200
Explanation
Introduction / Context:We compare the smaller inter-hand angle at two specified times and compute the percentage increase.
Given Data / Assumptions:
- At 2:00, hour angle = 60°, minute angle = 0° → smaller angle = 60°.
- At 6:00, hour angle = 180°, minute angle = 0° → smaller angle = 180°.
Concept / Approach:Percentage change = ((new − old)/old) * 100.
Step-by-Step Solution:Old (2:00) = 60°.New (6:00) = 180°.Increase = 180 − 60 = 120°.Percentage change = (120/60)*100 = 200%.
Verification / Alternative check:Graphing the smaller angle across hours shows it attains 180° at 6:00, confirming the calculation.
Why Other Options Are Wrong:100%/250% do not match the exact computation; “None” is wrong because 200% is valid.
Common Pitfalls:Using the reflex angle at 6:00 (also 180° here, but conceptually some problems request the smaller angle—identical here).
Final Answer:200 (percent).