Question

Six bells commence tolling together and toll at intervals of 2, 4, 6, 8, 10 and 12s respectively. In 30 min, how many times do they toll together?

Options

• 4

• 10

• 15

• 16

Answer 1

16

Explanation:
LCM, of 2, 4, 6, 8, 10, 12, is 120.
So, the bells will toll together after every 120 s (2 min).
In 30 min, they will toll together `30/2` + 1 = 16 times