Question

three Bells toll at intervals of 10 12 and 15 seconds respectively after how many seconds do the three Bells toll together

Answer 1

Just take the PCM of 10 12 and 15
which will be 60
so after every 1 minute they will toll together

Answer 2

HERE IS YOUR ANSWER

The answer is simple, you have to find the LCM of 10,12,15 = 60 seconds = 1 minute.

Therefore the three bells will simultaneously toll at an interval of 1 minute.

THANK YOU