Question

Three bells ring at regular intervals of 8.10 and 12 minutes. If they ring together at 6.00 am. When will they ring together again ?

Answer 1

LCM(8,10,12)
8=2*2*2
10=2*5
12=2*2*3
So, LCM=2^3*3*5=8*3*5=120minutes..
So they will toll together after 2 hours that is, 8.00a.m

Answer 2

$three \: bells \: ring \: together \: \\ = 8.10.12 \\ lcm \: of \: 81012 = 120 \\ the \: bell \: together \: at \: 12noon$