How to solve this algebra word problem

Question

Malik a chemist has a 32 %sulfuric acid solution and an 89% sulfuric acid solution on hand. If he mixes 12 liters of the 32% sulfuric acid and 5 liters of the 88^ sulfuric acid, what will be the percentage of the resulting sulfuric acid solution?

Answer 1

The formula I'm using is: (32x+89y)/(x+y)=avg

(32*12+89*5)/(12+5)=48.76%.

Answer 2

Use a weighted average for this problem:

(12 liters(32%) + 5 liters(88%))/(5 liters + 12 liters) = 824/17 = 48.47% sulfuric acid