Question

Two neon lights are turned on at the same time one blinks every four seconds and the other blinks every six seconds and 60 seconds how many times would the blink at the same time?

Answer 1

Five times

Explanation:

Start by finding the multiples of each number until they reach 60.

Multiples of four: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60

Multiples of six: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60

Look at both sets of multiples and see which ones they have in common (I put them in bold).

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

They have five common multiples, so they blink together five times within a minute.