Question

Three signals A, B, C changes to red very after 60 seconds, 30 seconds and 50
seconds respectively. If they become red together at 9 am, at what time will they
become red simultaneously again?

Answer 1

Answer:

At 9:05

Step-by-step explanation:

First you need to find the LCM of 30,50,60:-

Multiples of 30- 30, 60, 90, 120, 150, 180, 210, 240, 270, 300

Multiples of 60- 60, 120, 180, 240, 300

Multiples of 50- 50, 100, 150, 200, 250, 300

LCM-300

Next you need to turn 300 seconds into minutes:-

300 divided by 60 is 5

Now you need to add 5minutes to 9:00:-

9:05

Hope this was helpful!