The relation is 12 ounces of yellow paint with 5 ounces of blue paint. To find how many ounces of blue would be needed if you used 20 ounces of yellow, we can use the next proportion:
[tex]\frac{12\text{ ounces of yellow}}{20\text{ ounces of yellow}}=\frac{5\text{ ounces of blue}}{x\text{ ounces of blue}}[/tex]Solving for x,
[tex]\begin{gathered} 12\cdot x=5\cdot20 \\ 12\cdot x=100 \\ x=\frac{100}{12} \\ x=\frac{25}{3} \end{gathered}[/tex]You would need 25/3 ounces of blue paint
