Question

Four bells ring at an interval of 8 12 15 and 18 second resp. all the four begin to ring together . How many times will they ring together in one hour excluding the one at the start?

Answer 1

LCM of 8,1 2, 15, 18 = 360

So in every 360sec. ie. in every 6min. (360/60) all bell rang together.

no of times they ring together in one hr ie 60 min = 60/6 = 10times