4 bells toll together at 9 am. They toll after 7, 8. 11 and 12 seconds respectively. How many times will they toll together again in the next 3 hours?

5 times

Step-by-step explanation:

What we need to do here is to find the lowest common multiple of 7,8,11 and 12

This is;

1848

Now, let’s calculate the number of seconds in 3 hours

In 1 hour, we have 3600 seconds

In 3 hours, this will be;

3600 * 3 = 10,800 seconds

So, to find the number of times in which all 4 will toll together, we need to know the number of 1848 seconds in 10,800 seconds

Mathematically, that will be;

10,800/1848 = 5.844

Our answer will be 5 times however

This is because the sixth time they would have sounded together would be more than the 3 hours time frame