Question 264326
		        qty liters	strength%
solution A		x-12		10
				
solution B		12		20
				
solution C		x		14

.1*(x-12)+.2*(12) = .14*x

0.1x-1.2 + 2.4=0.14x

0.04x=1.2
x=1.2/0.04
30 liters

solution A = 18 liters