2 neon lights are turned on at the same time. One blinks every 4 seconds and the other every 6 seconds, how many times will they blink at the same time?
Ahh -- now your question makes sense.
The least common multiple of 6 and 4 is 12. They'll blink together every 12 seconds.
How many times will they blink together in 60 seconds?
The answer is 5
Because we need to find the lcm if 6 and 4 which is 12 then 60 divided by twelve is 5