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Three bells ring at intervals of 15, 20 and 30 minutes respectively. If they all ring at 11.00 a.m. together, at what time will they next ring together?

Three bells ring at intervals of 15, 20 and 30 minutes respectively. If they all ring at 11.00 a.m. together, at what time will they next ring together? Correct Answer 12 noon

L. C. M. of 15, 20 and 30 minutes = 60 minutes

Hence, the bells will ring together after 60 minutes.

∵ All the bells were ring at 11.00 a.m.

∴ At 12 noon, all the bells will ring together.

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