Question

the alarm on 2 mobile phones ring together once if one rings every 15 minutes and other rings and other rings every 25 minutes after how many minutes will ring together again​

Answer 1

ANSWER
Clocks will ring together again at L.C.M of 4,12,20
⇒LCM=4×1×3×5
=60
⇒ clocks ring together after 60 minutes.
solution