Question

A bell rings every 20 seconds. A second bell rings every 25 seconds. A third bell rings every 30 seconds. They all ring together at 8 p.m. how long will it be before all three bells ring together again?

Answer 1

To find the time it takes for all three bells to ring together again, we need to find the least common multiple (LCM) of their ringing times.

The LCM of 20, 25, and 30 is 300.

Therefore, all three bells will ring together again after 300 seconds.

Since there are 60 seconds in a minute, 300 seconds is equal to 300/60 = 5 minutes.

Therefore, all three bells will ring together again after 5 minutes.