Clock speeds — By how many degrees does the minute hand move in the same time that the hour hand moves by 28 degrees?

Difficulty: Easy

Correct Answer: 336

Explanation:


Introduction / Context:
This tests the constant angular speeds of clock hands. The minute hand moves 12 times as fast as the hour hand.


Given Data / Assumptions:

  • Hour hand speed = 0.5° per minute.
  • Minute hand speed = 6° per minute.
  • Hour hand displacement given = 28°.


Concept / Approach:
First find the time taken for the hour hand to move 28°, then compute the minute hand’s movement in the same time.


Step-by-Step Solution:
Time t = 28 / 0.5 = 56 minutes.Minute hand movement = 6 * 56 = 336 degrees.


Verification / Alternative check:
Using the 12:1 speed ratio: minute displacement = 12 * hour displacement = 12 * 28 = 336 degrees.


Why Other Options Are Wrong:
168 = 6 * 28/2 and 196/376 stem from incorrect speed ratios or arithmetic slips.


Common Pitfalls:
Forgetting the factor 12 or mixing time with angle directly.


Final Answer:
336 degrees.

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