Question

A manufacturer has 600 liters of 12% solution of acid. How many liters of a 30% acid solution must be added to it so that acid content in the resulting mixture will be more than 15% but less than 18%?

Answer 1

Let x liters of 30% acid solution is required to be added. 

Then, total mixture = (x + 600) liters. 

∴ 30% of x + 12% of 600 > 15% of (x + 600)

From (1) and (2) we get 120 < x < 300 

Thus, the number of liters of the 30% solution of acid will have to be more than 120 liters but less than 300 liters.