Question

Angelina is painting her room. She wants a very specific shade of bright blue paint, so she mixes blue and green paint in a ratio of 2:1. If she needs 6 gallons of paint, how many gallons of blue paint should she buy?

Answer 1

To find out how many gallons of blue paint Angelina should buy, we start with the ratio of blue to green paint, which is 2:1. This means that for every 2 parts of blue paint, there is 1 part of green paint.

Let's denote:

- The amount of blue paint as \( B \)
- The amount of green paint as \( G \)

From the ratio, we can express this as:

\[
\frac{B}{G} = \frac{2}{1}
\]

This means that \( B = 2G \).

Since Angelina needs a total of 6 gallons of paint, we have:

\[
B + G = 6
\]

Now, substituting \( B \) from our earlier expression:

\[
2G + G = 6
\]

Combining the terms gives us:

\[
3G = 6
\]

Dividing both sides by 3 gives:

\[
G = 2
\]

Now that we have the amount of green paint, we can find the amount of blue paint using \( B = 2G \):

\[
B = 2 \times 2 = 4
\]

Thus, Angelina should buy:

\[
\boxed{4}
\]

gallons of blue paint.