8th Class Mathematics Rational Numbers Question Bank Numbers

  • question_answer
    The bells begin tolling at the same time and continued to do so at intervals of 21, 28, 30 seconds respectively The bells will toll together again after

    A) 7 seconds                    

    B) 420 seconds

    C) 630 seconds                

    D) 1764 seconds

    Correct Answer: B

    Solution :

    The time after which they will toll together again must be a multiple of 21, 28 and 30. Hence LCM of 21, 28 and 30 is 420.


You need to login to perform this action.
You will be redirected in 3 sec spinner