Question 21.
A vessel contained a certain amount of a solution of acid and water. When 2 litres of water was added to it, the new solution had 50% acid concentration. When 15 litres of acid was further added to this new solution, the final solution had 80% acid concentration. The ratio of water and acid in the original solution was
Question Explanation
Let's start from the step when there was 50% concentration.
Let's assume total 2T solution: T acid and T water.
Adding 15 litres of acid increases the acid concentration to 80%, giving the equation
Solving this would give us T=5
This means that there were 5 litres of acid and 5 litres of water after mixing 2 litres of water.
Therefore, there would be 5 litres of acid and 3 litres of water before adding the water.
We are asked the ratio of water to acid, which would be 3:5
Therefore, Option B is the correct answer.
