A pharmaceutical company prepares a new drug by mixing two compounds, Compound P and Compound Q. The final mixture has a total mass of 150 grams and is 73% active ingredient by mass. Compound P contains 55% active ingredient, and Compound Q contains 85% active ingredient. If the mass of Compound P used is 30 grams less than the mass of Compound Q used, what is the mass, in grams, of Compound Q?
