SSC CHSL 2025 PYQ — Question 55

SSC CHSL - 28 Nov 2025 - Shift 1 • Quantitative Aptitude • Q55

A solution contains 80% acid. How much water must be added to 20 liters of this solution to make acid 50%?

Show answer & explanation

Correct answer: A

Explanation

Given:

Solution = 20 L

Acid = 80%

Final Acid Concentration = 50%

According to the formula:

Amount of Acid = (Percentage / 100) × Total Solution

Initial Acid = (80 / 100) × 20 = 16 L

Let the amount of water added be x L.

New Total Solution = (20 + x) L

Acid Percentage = 50%

16 / (20 + x) = 50 / 100

16 / (20 + x) = 1 / 2

32 = 20 + x

x = 12

Water added = 12 L