2 traffic lights are turned on at the same time. 1 blinks every 4 seconds and. the other blinks ever

2 traffic lights are turned on at the same time. 1 blinks every 4 seconds and. the other blinks every 6 seconds. In 60 seconds how many times will they blink at the same time?

We want the least common multiple of 4 and 6 which is 12.

So ever 12 seconds, both lights blink together:

1. 12
2. 24
3. 36
4. 48
5. 60

So our answer is 5 times