Question

Six bells commence tolling together and toll at intervals of 3, 6, 9, 12, 15, 18 seconds

respectively. In 1 hr. 30 mins., how many times do they toll together? ◯ (a)31

◯ (b)28

◯ (c) 29

◯ (d)32​

Answer 1

Answer:

29 according to me....!

Step-by-step explanation:

hope it helps

Answer 2

Given:

Total number of bells = 6

Intervals at which they toll = 3, 6, 9, 12, 15, 18

To Find:

How many times do they toll together in 1 hour 31 minutes

Solution:

The LCM of 3, 6, 9, 12, 15, 18 is 180.

Now the time is 1 hour 30 minutes, which means -

60 + 30

= 90 Minutes,

Converting to seconds -

= 90 × 60

= 5400

Thus, number of times they toll together -

= 5400/180

= 30

They basically also toll at the beginning. So, total tolls together will be -

= 30 + 1

= 31

Answer: 31 times they toll together in 1 hour 31 minutes