Question 272631
<pre>
PERCENT           VOL.          PURE
 100               v             1.0v
  10               6             0.1*6
  20              v+6           v+0.1*6
</pre>

{{{(v+0.1*6)/(v+6)=0.2}}}


{{{v+0.6=0.2(v+6)}}}
{{{v+0.6=0.2v+1.2}}}
{{{v-0.2v=1.2-0.6}}}
{{{0.8v=0.6}}}

{{{highlight(v=3/4)}}}