Three bells toll of intervals of 10 minutes , 15 minutes and 20 minutes. If they toll together at 11:00am ,when next do they toll together again
The bells will toll together again when their intervals align and they all ring at the same time.
To find the next time they will toll together, we need to find the least common multiple (LCM) of the intervals of 10, 15, and 20 minutes.
The prime factors of 10 are 2 and 5.
The prime factors of 15 are 3 and 5.
The prime factors of 20 are 2, 2, and 5.
To find the LCM, we need to take the highest power of each prime factor that appears in any of the numbers:
2^2 x 3 x 5 = 60
Therefore, the bells will toll together again in 60 minutes, or 1 hour.
Since they first tolled together at 11:00am, they will toll together again at 12:00pm (noon).