SSC CPO 2024 PYQ — Question 124

The correct answer is option 2 i.e 6

Volume of mixture = 12 L

Amount of acid in the mixture = 30%

According to the given question,

The initial amount of acid in the mixture = 30% of the total volume

⇒ 30% of 12 L = 3.6 L

The amount of water in the mixture(12 - 3.6) = 8.4 L

Let the amount of water added in the mixture be x L.

Now, ${Amount\ of\ acid \over Total\ volume} \times 100 = 20$

⇒ ${3.6 \over 12 + x} \times 100 = 20$

⇒ 12 + x = 18

⇒ x = 6

Hence, the water to be added is 6 L.