Question 851012
This is just a different example of the same general problem as explained (but not fully solved) in here:


<a href="http://www.algebra.com/algebra/homework/word/mixtures/Mixture_Word_Problems.faq.question.851007.html">Percent w/v Mixture, unknown quantities to use, known conc and quantity of result</a>


If the example is percents volume per volume, you simply not need the densities.