Question

In a school, the duration of a class in the primary section is 40 minuntes , and in the secondary section it is 1 hour. if both sections begins at 9 a.m., when will bells of the two sections ring together again?
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Answer 1

卂иรωεƦ:-✌✌

find the LCM of 40 and 60 .that is 120

so after 120 mins both bells will ring together

it means after 2 hours

9 + 2 = 11 a.m.