Question 513657
	--------price	----------------	quantity									
Coffee I	90	----------------			50	lbs						
coffee II	60	----------------			x	lbs						
Mixture	70	----------------	50	+	x	lbs						
												
90*50+60	x=70(50	+x)
4500+60	x=3500	+	70	x				
60	x	+	-70	x	=	3500	-	-4500				
-10	x	=	-1000									
/	-10											
x	=	100										
		100	lbs		of	60	%	coffee II