Six bells commence tolling together, afterwards, they toll at intervals of 2, 4, 6, 8, 10 and 12 seconds respectively. In 30 minutes, how many times do they toll together?
1
4
2
16
3
15
4
More than one of the above
5
None of the above
Six bells commence tolling together, afterwards, they toll at intervals of 2, 4, 6, 8, 10 and 12 seconds respectively. In 30 minutes, how many times do they toll together?