I am having trouble, I have a question I think I got the answer because I kept multiplying and dividing, but I have to show my work but when i try, my answer is not the same.

The question is A traffic light at one intersection changes every 28 seconds and the light at the other intersection changes every 32 seconds. How long until they both change together?

I got every 8 light changes. Can you please help me solve this?

5 answers

sorry forgot to put math.
I got it, it is every 224 seconds. I had to find the LCM to find the GCF. I then had to multiply 28 and 32 to divide the GCF which gave me 224. Thanks anyway.
Definitely not 2nd grade..
it is 1,235,1469,2587,265,874 times 1million
don't listen to bill.

he is in high school.