Question 729631
<pre>
Concentration, %          Volume, liters                pure hydrogen peroxide
          8                       v+2                        0.08(v+2)
         10                       8-(v+2)-v=6-2v            0.1(6-2v)
         20                        v                         0.2v
TOTAL    12.5                      8
</pre>
{{{(8(v+2)+10(6-2v)+20v)/8=12.5}}}, to represent the final concentration.
Simplify and solve....