Difficulty: Easy
Correct Answer: 22
Explanation:
Introduction / Context:
The hands coincide 11 times in 12 hours (not 12, since the minute hand “laps” the hour hand slightly less than once per hour). Over a full day, this doubles to 22 coincidences.
Given Data / Assumptions:
Concept / Approach:
Use the standard count of overlaps per 12 h and multiply by 2.
Step-by-Step Solution:
Verification / Alternative check:
Average interval between overlaps is about 65 5/11 minutes; 24 h / (65 5/11 min) ≈ 22.
Why Other Options Are Wrong:
24 and 12 assume one per hour or one per 2 hours incorrectly; 20 undercounts.
Common Pitfalls:
Assuming exactly once per hour; the hour hand moves steadily, so the minute hand cannot lap exactly 12 times in 12 hours.
Final Answer:
22
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