Question

A blue neon light blinks every 4 seconds. A red one blinks every 5 seconds while a green one blinks every 6 seconds. How many times will they blink together in half an hour?

Answer 1

Answer:

In order to solve, we first need to find the LCM (least common multiple) of 4, 5, and 6

The prime factors are

4: 2,2

5: 1,5

6: 1,6

So the LCM is 60.

That means every 60 seconds (1 minute) they blink together.

There are 30 minutes in a half an hour, so they blink together 30 times.

Step-by-step explanation:

Answer 2

Answer:

solution

find the LCM of 4,5 and 6 seconds

LCM=60 seconds

time conversion:

1 minute=60 seconds

1hr=60 minutes

1/2 hr=30 minutes

then

30 minutes÷1 minute

=30 blinks altogether in half an hour