We have the following:
The first thing is to calculate the ratio between both paintings.
After finding the ratios, it can be calculated for any value using a proportionality rule.
![(2)/(10)=(1)/(5)](https://img.qammunity.org/2023/formulas/mathematics/high-school/hzut5xw7ormge06m4sj3mro58ac7y9yx9x.png)
for example, for 5 cups of blue paint, should be for yellow paint:
![\begin{gathered} (1)/(5)=(5)/(x) \\ x=(5\cdot5)/(1) \\ x=25 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/gsfwlcolam3jz1mzdpeqf1ye7ybx8f8fzq.png)
therefore, should be 25 cups of yellow paint