Question 405972
percent	----------------	quantity		
30	----------------	20  brass
100	----------------	x    Zinc
40	----------------	20+x  Mixture


30*20+100*x=40(20+x)
	
600+100	x=800+40x				
			
100x-40x=800-600					
									
60x=200										
													
/60													
x=3.33	ounces of pure Zinc