Firstly, I would just like to add, this question is not a homework problem. If I go through a book and stumble across a question I could not solve, I will always write it down and return to it at a later date (hoping I will solve it). Anyway, I was cleaning out my room and found a scrap piece of paper with a problem on (from a level 1 GCSE book) I remembered I could not solve, and it's still the case today. So here's the question: x g of cartridge brass (70% copper, 30% zinc, by mass) and y g of naval brass (62% copper, 37% zinc, 1% tin, by mass) when fused together give a new alloy containing 342.6g of copper and 165.6g of zinc. Find x and y. Answer: x = 330, y= 180. It's always been the 1% tin that's made the problem more ugly (maybe this is not so for others). Will someone out there please put me out my misery. Thank you.