Question

4 bells ring at intervals of 30 minutes, 1 hour, 1 hour 30 minutes and 1 hour 45 minutes respectively. All the bells ring simultaneously at 12 noon. They will again ring simultaneously at:/4

Answer 1

First convert the durations into minutes. We have:30, 60,90 and 105 respectively.
We get the LCM:the lcm is 1260minutes
We convert the minutes into hours :1260/60=21hrs
The bells ring together after 21hours.
The next time they will ring together is:12:00+21.00=9.00a.m the following day.
More details on lcm and calculations are in The image below.

Answer 2

Step-by-step explanation:

bells ring at intervals of 30 minutes, 1 hour, 1 hour 30 minutes and 1 hour 45 minutes respectively. All the bells ring simultaneously at 12 noon. They will again ring simultaneously at:/4

Answer 9 am