If the ratio white pens to green pens is 2 to 8 and there are a total of 30 pens how many pens are white.

The answer to the question is 120 because you can do the butterfly method 2

2:8

30:x

cross multiply it

There are thirty pens for every 2 white pens there are 8 green pens which means for every 10 pens there are 2 white pens. 30 pens total divided by 10 pens is 3. take the 2 white pens and multiply by that 3 to get 6. there are 6 white pens