A mixture contains acid and water in the ratio 4 : 3. If 5 liters of water is added to the mixture, the ratio becomes 4 : 5. Find the quantity of acid in the given mixture.

Question: A mixture contains acid and water in the ratio 4 : 3. If 5 liters of water is added to the mixture, the ratio becomes 4 : 5. Find the quantity of acid in the given mixture.

Solution:
Let the quantity of acid and water be 4x liters and 3x liters respectively

ATQ,
4x/(3x + 5) = 4/5
⇒ 20x = 4(3x + 5)
⇒ 20x = 12x + 20
⇒ 8x = 20
∴ x = 2.5

Quantity of acid
= (4 × 2.5) liters
= 10 liters