Hey,

A bag contains counters that are RED, BLACK, or GREEN.

"1 OVER 3" are red

"1 OVER 6" are black

There are 15 green counters in the bag. How many black counters are in the bag?

I multiplied the "1 OVER 3" by 2 to get

"2 OVER 6"

So then its the same as the black ones, so green must be:

"3 OVER 6"

And so..Im not sure how what to do from here...

Thanks