Question:medium

How many litres of water will have to be added to 1125 litres of the 45% solution of acid so that the resulting mixture will contain more than 25% but less than 30% acid content?

Updated On: Jan 23, 2026
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Solution and Explanation

Given:

Volume of acid solution = 1125 litres 
Percentage of acid = 45%

Amount of acid present 
= 45% of 1125 
= 506.25 litres


Let:

x litres of water be added.

Total volume of new solution = (1125 + x) litres


Condition 1: Acid content more than 25%

Acid percentage > 25%

\(\frac{506.25}{1125 + x} > \frac{25}{100}\)

506.25 > 0.25(1125 + x)

506.25 > 281.25 + 0.25x

225 > 0.25x

x < 900


Condition 2: Acid content less than 30%

Acid percentage < 30%

\(\frac{506.25}{1125 + x} < \frac{30}{100}\)

506.25 < 0.30(1125 + x)

506.25 < 337.5 + 0.30x 

168.75 < 0.30x

x > 562.5


Final Answer:

To satisfy both conditions,

562.5 litres < x < 900 litres

Hence, the quantity of water to be added must be 
more than 562.5 litres but less than 900 litres.

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