Question

The lights on three lightships flash at regular intervals lights flashes every 18 seconds, the second every 30 seconds and the third every 40 seconds .the three lights flash together at 10.00pm .at what time will they next flash together?​

Answer 1

Step-by-step explanation:

We will take l.c.m. of 18,30&40

This comes out to be 360 seconds.

Now,convert 360 seconds into minutes.

We know,for converting seconds into minutes,we divide by 60

=>360seconds=360/60minutes=6minutes

Last time,the three lights flashed together at 10.00pm.

Therefore,they will now flash after 6minutes i.e.at 10.06pm