Two lighthouses can be seen from the top of the hill. The first flashes once every 3 seconds and the other flashes once every 5 seconds. If they flash at the same time, how long will it be before they flash at the same time again? About the author Madelyn
We know that first flashes once every 3 seconds and the other flashes once every 5 seconds, Therefore we need to take the LCM of those two numbers 3- 3,6,9,12,15 5- 5,10,15 Therefore after 15 seconds they both will flash at the same time. Reply
We know that first flashes once every 3 seconds and the other flashes once every 5 seconds,
Therefore we need to take the LCM of those two numbers
3- 3,6,9,12,15
5- 5,10,15
Therefore after 15 seconds they both will flash at the same time.