A solution contains acid and water in the ratio of 4 : 5. If 20% of the solution is replaced by water, then what will be the ratio of acid and water in the new solution?
Answer & explanation
Correct answer: option 3
Here,
Ratio of acid and water = 4 : 5
⇒ Let the total solution be 90 units,
⇒ Amount of acid = 90 × \(\frac{4}{9}\) = 40 units
⇒ Amount of water = 90 × \(\frac{5}{9}\) = 50 units
⇒ 20% of the total solution is taken out = 90 × \(\frac{20}{100}\) = 18 units
⇒ Acid and water will be taken out in 4 : 5
⇒ Remaining amount of acid = 40 - 18 × \(\frac{4}{9}\) = 32
⇒ Remaining amount of water = 50 - 18 × \(\frac{5}{9}\) = 40
The amount taken out is replaced with water;
So, new quantity of water = 40 + 18 = 58
Therefore, The ratio of acid and water in the new solution = 32 : 58 = 16 : 29