Initially we have 3 quarts of a 50% antifreeze solution
We want to obtain a 60% antifreeze solution by adding x quarts of pure antifreeze
Therefore we can set the following equation,
[tex]1x+0.5*3=0.6*(x+3)[/tex]
where x are the quarts of pure antifreeze added
let's solve for x
[tex]\begin{gathered} x+1.5=0.6x+1.8 \\ x-0.6x=1.8-1.5 \\ 0.4x=0.3 \\ x=\frac{0.3}{0.4} \\ x=0.75 \end{gathered}[/tex]
rounding to the nearest tenth, 0.8 quarts of pure antifreeze must be added
