**Q) **Three bells ring at intervals of 6, 12 and 18 minutes. If all the three bells rang at 6 a.m., when will they ring together again?

**Ans: **

The three bells will ring together again when the time gap is perfect multiple of each bell’s interval

Therefore, we will take LCM of three time intervals

LCM of 6, 12, 18 = 6 x 2 x 3 = 36 minutes

New time of ringing together = 6:00 am + 36 mins = 6:36 am

**Therefore, three bells will ring together at 6:36 a.m. **