Question

    data-sheets-value="{"1":2,"2":"Five bells commence tolling together and tolls at intervals of 2, 6, 10, 18 and 24 seconds respectively. In 36 minutes, how many times do they toll together? "}" data-sheets-userformat="{"2":4993,"3":{"1":0},"10":2,"11":4,"12":0,"15":"arial,sans,sans-serif"}">Five bells commence tolling together and tolls at intervals of 2, 6, 10, 18 and 24 seconds respectively. In 36 minutes, how many times do they toll together?
    A 7 Correct Answer Incorrect Answer
    B 9 Correct Answer Incorrect Answer
    C 11 Correct Answer Incorrect Answer
    D 13 Correct Answer Incorrect Answer

    Solution

    First time, 5 bells will toll together on = LCM (2,6,10,18 & 24sec) = 360 sec = 6 min
    In 36 minutes , they will toll together = 36 /6 = 6 times
    But it is also given that they commence tolling together at starting time so answer is 6 + 1 = 7.

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