A painter plans to paint a room with an area of 515 square feet. He mixes paint to create a specific shade of green. The ratio of each color in his mixture is shown.

1 part blue paint
3 parts yellow paint
2 parts white paint
The painter estimates that he will need 1 gallon of green paint for every 175 square feet of the room. He estimates the smallest number of whole gallons of green paint needed to paint the room. How much blue paint will the painter need to make this batch of green paint? the answer to that is 1/2 (but that there since I need help with part 2)

The painter makes a second batch of green paint using the same ratio of blue, yellow, and white paint.

1 part blue paint
3 parts yellow paint
2 parts white paint
If uses 3 gallons of white paint to make the batch, how many total gallons is this batch of green paint?

pls explian the second part :)