Question 985572
<a href="https://www.youtube.com/watch?v=-REjxT9KCzQ">Same idea but different kind of concentration and different kind of material</a>


A lesson for this more generally:
<a href="http://www.algebra.com/my/mixture-price-two-part-both-parts-unknown.lesson?content_action=show_dev">http://www.algebra.com/my/mixture-price-two-part-both-parts-unknown.lesson?content_action=show_dev</a>