GCSE Secondary Maths Age 13-17 - Number: LCM and HCF - Explained

The video tutorial explains a problem involving three lamps that flash at different intervals. The task is to determine how many times the lamps flash simultaneously in one hour. The solution involves finding the lowest common multiple (LCM) of the intervals, which is 360 seconds. This means the lamps flash together every 6 minutes, resulting in 10 flashes in an hour. The tutorial also discusses the marking scheme and the possibility of an alternative answer if the first flash is considered at time zero.

What is the flashing interval of lamp A?

Calculate the lowest common multiple (LCM) of the flashing intervals of the three lamps.

How many times do the three lamps flash at the same time in one hour?

If the first flash occurs at t equals 0, how many times will the lamps flash together?

Explain the reasoning behind the calculation of the number of times the lamps flash together.