Nate is helping to redesign his basement. He is in charge of choosing and buying the paint. He wants a specific shade of green, so he is going to combine blue and yellow paint in the ratio of 1:3 . If he needs 8 gallons of paint, how much yellow paint does he need to buy?

The total ratio of blue to yellow paint is 1 + 3 = <<1+3=4>>4

The proportion of yellow paint needed is 3/4 = <<3/4=0.75>>0.75
He needs to buy 8 * 0.75 = <<8*0.75=6>>6 gallons of yellow paint. Answer: \boxed{6}.

To find out how much yellow paint Nate needs to buy, we need to determine the ratio of yellow paint to the total amount of paint.

The total ratio of blue to yellow paint is 1:3. This means for every 1 part of blue paint, Nate needs 3 parts of yellow paint.

Let's determine the total number of parts in the ratio:
1 + 3 = 4 parts

To calculate the amount of yellow paint needed, we divide the total amount of paint required (8 gallons) by the total number of parts in the ratio (4).

Yellow paint needed = (Total yellow paint parts / Total parts) * Total paint
= (3 / 4) * 8
= 6 gallons

Therefore, Nate needs to buy 6 gallons of yellow paint.

To find out how much yellow paint Nate needs to buy, we first need to determine the ratio in terms of gallons of paint for blue and yellow.

The ratio given is 1:3, which means that for every 1 gallon of blue paint, Nate needs 3 gallons of yellow paint.

Since Nate needs a total of 8 gallons of paint, we'll need to set up a proportion to find out how much yellow paint he requires.

Let's assign 'x' to represent the gallons of yellow paint needed:

1 gallon of blue paint / x gallons of yellow paint = 8 gallons of blue paint / 8 gallons of yellow paint

Now, cross-multiply the proportion:

1 gallon of blue paint * 8 gallons of yellow paint = 8 gallons of blue paint * x gallons of yellow paint

8 gallons of yellow paint = 8 gallons of blue paint * x gallons of yellow paint

Simplifying further, we get:

8 = 8x

Divide both sides of the equation by 8:

8/8 = 8x/8

1 = x

Therefore, Nate needs to buy 1 gallon of yellow paint in order to achieve the desired ratio of 1:3 and obtain a total of 8 gallons of paint.