Difficulty: Easy
Correct Answer: 39°
Explanation:
Introduction / Context:
Compute the smaller angle between hands at a specific time using angle formulas.
Given Data / Assumptions:
Concept / Approach:
Use angle difference = |(30h + 0.5m) − 6m|.
Step-by-Step Solution:
Hour angle = 30*2 + 0.5*18 = 60 + 9 = 69.Minute angle = 6*18 = 108.Difference = |69 − 108| = 39 degrees.
Verification / Alternative check:
The reflex angle would be 360 − 39 = 321, so the standard (smaller) angle is 39 degrees.
Why Other Options Are Wrong:
37° and 33° arise from arithmetic slips; “None” is wrong because 39° is exact.
Common Pitfalls:
Neglecting the hour-hand movement during the 18 minutes.
Final Answer:
39°.
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