Interview Question: Clock Hands

Sample Question #121 (brainteaser)

How many times do the hour and minute hands of a clock overlap during the 24-hour day? Let’s assume the day runs from 12 midnight to 12 midnight.

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One Response to Interview Question: Clock Hands

  1. Brett says:

    ANSWER
     
    You need to notice (and tell the interviewer) two things:
     
    1) The hour and minute hands overlap in every hour except when the hour is 11.
    3) Since midnight is included twice, we have a total of 3 12 o’clock readings.
     
    So the final answer is 10*2 + 3 = 23.
     

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