Question

Six bells commence tolling together and toll at intervals of 2, 4, 6, 8 10 and 12 seconds

respectively. In 30 minutes, how many times do they toll together ?​

Answer 1

Number of tolls in 30 minutes= 2*30 = 60 times

{Cause there is difference of 2 in the intervals.}

Answer 2

The least common multiple (LCM) of 2, 4, 6, 8, 10, and 12 is 120. Thus, the bells toll together every 120 seconds (or 2 minutes), so in 30 minutes they will toll simultaneously 30/2 = 15 times.