Quantity of 45% acid solution = 1125 litres
Quantity of acid =
Suppose x litres of water is added
∴ Quantity of acid =
Total quantity of mixture = (1125 + x) litres
% of acid content =
According to the problem,
Now, ...(i)
Also,
...(ii)
From (i) and (ii), we have
Hence, a minimum of 562.5 litres and a maximum of 900 litres of water be added so as to move a solution with 25% to 30% of acid content.