Question 1157206
<pre>
        VOLUME    PURE ACID

20%        x       0.2x

40%        y       0.4y

60%       3y      0.6*3y

50%       84
</pre>


{{{system(x+4y=84,0.2x+2.2y=0.5*84)}}}


{{{system(x+4y=84,x+11y=210)}}}


{{{E2-E1}}}:

{{{7y=126}}}

{{{highlight(y=18)}}}, and you can find the other two.