Question

Faith mixes 14 liters of 12% acid solution with a 30% acid solution, which results in an 18% acid solution. How many liters of 30% solution did she use? A. 4.7 liters B. 21 liters C. 12 liters D. 7 liters. please help will give brainiest!

Answer 1

x = liters of 30% acid
0.12*14 + 0.30x = 0.18(x + 14)
1.68 + 0.30x = 0.18x + 2.52
0.30x - 0.18x = 2.52 - 1.68
0.12x = 2.52 - 1.68
x = (2.52 - 1.68)/0.12
x = 7
Answer:
7 liters of 30% acid