Answer:
4 gallons
Explanation:
6 gallons of paint means she needs 2 gallons of blue paint per 1 gallon of green paint.
To make the proper mixture, you need 3 gallons with 2 blue and 1 green. This means you do 6/3=2. You can make 2 total mixtures.
Multiply 2 blue by the 2 mixtures we need to make. You get 4 gallons of blue paint.
Multiply 1 green by the 2 mixtures we need to make. You get 2 gallons of green paint.
Check your work:
4+2=6
4/2=2:1