Question

Three bells in the church toll at interval of 15,18 and 45 second respectively. After how many seconds will the three bells toll together?​

Answer 1

Answer:

After 90 seconds and every 90 seconds thereafter

Step-by-step explanation:

First bell will toll at intervals of 15 seconds; second in 18 seconds and third in 45 seconds.

The first time that all the bells will toll together will be the least common multiple (LCM) of 15, 18 and 45

LCM of 15,18,45 = 90

The first time that all the bells will toll together will be at 90 seconds.

It is also clear that the second time, the bells will toll together will be at 180 seconds, then at 270 seconds, and so on.

Hence, the bells will toll after 90 seconds, and at every 90 seconds thereafter.

Simultaneous tolling interval (seconds): 90, 180, 270, etc.          

Answer 2

Step-by-step explanation:

LCM of 15,18 and 45 is 90

ie they all will ring together simultaneously after 90 mins