CBSE Class 11-science Answered

Let us assume that l liters of water is added to 1125 liters so that the resulting mixture contain more than 25% but less than 30% acid solution.

Lets first calculate the acid content in 1125 liters (45% acid).

i.e., liters

Now when l liter of solution is added so the volume becomes (1125 + l) liter.
  Now according to question the acid content should be more than 25% but less than 30% so

Now this can be written as two inequalities,

 and

Multiplying by 100

Solving 2^nd inequality

then    

Hence the quantity of water added should be greater than 562.5 litre but less than 900.