Marty has available a 20% alcohol solution and a 70% alcohol solution. How many liters of each solution should be mixed to make 30 L of a 50% alcohol solution?
+36916 x = 20 %
30 -x = 70%
20% x + 70% (30-x) = 50% (30)
.2x + 21 - .7x = 15
x = 12 l of 20% 18 l of 70 %
