Question

How many quarts of pure antifreeze must be added to 3 quarts of a 50% antifreeze solution to obtain a 60% antifreeze solution?quart(s) of pure antifreeze must be added(Round to the nearest tenth as needed.)

Answer 1

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,

$1x+0.5*3=0.6*(x+3)$

where x are the quarts of pure antifreeze added

let's solve for x

$\begin{gathered} x+1.5=0.6x+1.8 \\ x-0.6x=1.8-1.5 \\ 0.4x=0.3 \\ x=\frac{0.3}{0.4} \\ x=0.75 \end{gathered}$

rounding to the nearest tenth, 0.8 quarts of pure antifreeze must be added