Question

Traffic lights at three diferent junctions change simultaneously at morning 8.00 am. The first light changes once in 30 seconds, the second once in 72 seconds, the third once in 45 seconds. After 8.00 am which is the next time they change simultaneously?,​

Answer 1

Answer:

The next time they change simultaneously

is 8:06 am

Step-by-step explanation:

First we have to take LCM of 30 sec , 72 secs and 45 secs i.e 360 secs = 6 mins

So, the they will change after 6 mins.

Thus, the next time they change simultaneously

is 8:06 am

Answer 2

The answer is they will simultaneously glow at 8:06 am.

First take out the LCM of 30 , 45 , 72 secs and convert to minutes and add to the the time given