Question

A red light flashes 3 times per minute and a green light flashes 5 times in two minutes at regular intervals. If both lights start flashing at the same time, how many times do they flash together in each hour?

Answer 1

Answer:

Red light 1800time

green light 1500 time

Answer 2

Answer:

30 times.

Step-by-step explanation:

Red light flashes every 30 secs ( 60min / 3 times)

Green light flashes every 24 secs(120 min / 5 times)

And LCM of 20 and 24 = 120

So both lights will flash every 120 secs

The ans needs to be in hour.

So, 3600/120 = 30 times.