A gardener combines x fluid ounces of a 20% liquid fertilizer and 80% water mix with y fluid ounces of a 5% liquid fertilizer and 95% water mix to make 30 fluid ounces of a 10% liquid fertilizer and 90% water mix.

Question

A gardener combines x fluid ounces of a 20% liquid fertilizer and 80% water mix with y fluid ounces of a 5% liquid fertilizer and 95% water mix to make 30 fluid ounces of a 10% liquid fertilizer and 90% water mix.  
a. Write a system of linear equations that represents the situation.
b. Solve the system from part (a).
c. Suppose the gardener combines pure (100%) water and the 20% liquid fertilizer and 80% water mix to make the 30 fluid ounces of the 10% liquid fertilizer and 90% water mix.  Is more of the 20% liquid fertilizer and 80% water mix used in this mix than in the original mix?  Explain.