Question

Three Bells Chime At An Interval Of 12, 24 And 36 Minutes Respectively. At A Certain Time They Begin To Chime Together. What Length Of Time Will Elapse Before They Chime Together Again?​

Answer 1

Solution:

Three bells ring at intervals of 20 minutes 30 minutes and 45 min respectively

LCM is the least common factor that is divisible

by all the numbers.

The bell will again rang together after the time which is equal to LCM of the times.

So, we need to find the LCM of 20, 30 and 45.

Factors of 20 = 1\times2\times5\times2

Factors of 30 = 1\times2\times5\times3

Factors of 45 = 1\times3\times5\times3

So the LCM of 20, 30 and 45 min is = 180 min

Hence, the bells will ring together after 180 min

= 3 hours.