<PRE><B>Question 813502</B>
You want 350 liters of a solution with 12% acid. You have two solutions, one is 16% and the other is 9%.
 How many liters of the 16% solution will be needed?
:
Let x = amt of 16% solution
total is to be 350 liters, therefore
(350-x) = amt of 9% solution
:
.16x + .09(350-x) = .12(350) 
.16x + 31.5 - .09x = 42
.16x - .09x = 42 - 31.5
.07x = 10.5
x = 10.5/.07
x = 150 liters of the 16% solution</PRE>