Question

Three balls ring at an interval of 15,20 and 25 minutes. If they ring together at 10 am at what time they ring together again​

Answer 1

LCM of 15, 20 and 25 = 300

So they will ring together again

at 10 AM + 300 minutes = 10 + 5 hours = 15 hours = 3 PM

Answer 2

Take LCM of 15, 20, 25

so, the LCM = 300

so in hours = 10+300/60

=10+5

= 15

= 3 pm