New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    Five bells commence tolling together and toll at

    intervals of 2, 4, 9, 12 and 15 seconds respectively. In 45 minutes, how many times do they toll together?
    A 8 Correct Answer Incorrect Answer
    B 10 Correct Answer Incorrect Answer
    C 16 Correct Answer Incorrect Answer
    D 15 Correct Answer Incorrect Answer

    Solution

    LCM of the time intervals will be 2,4,9,12, and 15 will be 180. 1 min = 60 seconds. 180 seconds = 180/60 = 3 minutes. Therefore number of times they all toll together = (45/3)  + 1 = 16 times.

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