Let's begin by identifying key information given to us:
From the picture, 3 tablespoons of blue paint is equal to 1 cup of white paint
![3Tablespoons(BluePaint)=1cup(WhitePaint)](https://img.qammunity.org/2023/formulas/mathematics/college/ydbsh29ou1mj1yd2o90d5z7w3z5rvpd81x.png)
To calculate how many cups of white paint is needed to mix 12 tablespoons of blue paint, we have:
![\begin{gathered} 3Tablespoon(blue)=1cup(white) \\ 12Tablespoon(blue)=x \\ We\text{ will cross multiply, we have:} \\ 3\cdot x=1\cdot12 \\ 3x=12 \\ x=(12)/(3)=4 \\ x=4cup(white) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/fem7g09sg3wqnxzh74rxtgeywrr3idh67b.png)
This means that Elena will require 4 cups of white paint to mix 12 tablespoons of blue paint