Question 534061
8%--------------------x
9%--------------------y

10%-------------------z

x=4z

therefore 8% -----------4z

4z+y+z=775000
5z+y=775000...................(1)

0.08*4z+0.09y+0.1z=67500
0.32z+0.09y+0.1z=67500
0.42z+0.09y=67500.............(2)

5	z	+	1	y	=	775000	.............1	
0.42	z	+	0.09	y	=	67500	.............2	
Eliminate y								
multiply (1)by 		-0.09						
Multiply (2) by		1						
-0.45	z		-0.09	y	=	-69750		
0.42	z		0.09	y	=	67500		
Add the two equations								
-0.03	z				=	-2250		
/	-0.03							
z	=	75,000.00						
plug value of 			z	in (1)				
5	z	+	1	y	=	775000		
375000		+	1	y	=	775000		
			1	y	=	775000		-375000
			1	y	=	400000		
				y	=	400000.00		
10% ------------$75000						
9%--------------$400000	
8%--------------4*75000= $300000

CHECK

75000*0.1+400000*0.09+300000*0.08=67500

						
m.ananth@hotmail.ca