Question

The traffic lights at three different road crossing change after every 48 seconds, 72 seconds and 108 seconds respectively.If they change simultaneously at 7 am,at what time will they change simultaneously again?

Answer 1

after 432 s
tht is 7:07:12

Answer 2

First find the LCM of the given numbers. It is the second which when the three traffic lights change simultaneously. Convert it into minutes. Then add to 7 am. The answer above is correct.