Question

A bell rings every 10 minutes and a buzzer sounds every 15 minutes. If the bell and buzzer both sound at 8 a.m., what is the next time that they will both go off at the same time?

Answer 1

I Think The Answer is :-
Just Take LCM(10,15)

30 Mins

=> 8:30am

Hope it'll Help You.....

Have a great day.....

Answer 2

LCM of 10 and 15 minutes = 2 × 3 × 5 = 30 minutes
The bell and the buzzer will sound next at 8 hour + 30 minutes = 8 :30 a.m.