Question

16 L of a solution containing 15% acid are mixed with 20 L of another solution containing 16% acid. 4 L of water was then mixed with the resulting solution. What is the percentage of water in the final solution?
1. 86
2. 82
3. 80
4. 88

Answer 1

Correct Answer - Option 1 : 86

16 L of a solution containing 15% acid,

Acid = 15% of 16 = 2.4 L

 20 L of another solution containing 16% acid

Acid = 16% of 20 =  3.2 L

Total Mixture = 16 + 20 + 4 = 40 L

percentage of water = (13.6 + 16.8 + 4) × 100/40

percentage of water = 86%