In order to find this, we need to count exactly how many times each of them blinks within 60 seconds. Then, we find which numbers are the same.
4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60
6, 12, 18, 24, 30, 36, 42, 48, 54, 60
Now, I will bold the numbers that are the same.
4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60
6, 12, 18, 24, 30, 36, 42, 48, 54, 60
Now, we have our answer.
Answer: The two neon lights will blink on the 12, 24, 36, 48, and 60 second marks.
Hope I helped!