Question 432958
------	Percent	----------------	quantity										
salt solution	10	----------------4								
salt solution	40	----------------x								
Total	30	----------------4+x								
													
10*4+40*x=30(4+x)
40+40x=	120+30x					
40x-30x=120-40					
10x=80										
/10									
x=8 liters 40%salt solution