A cask P is filled with 50 liters of water, and cask Q with 40 liters of acid. Precisely x liters are drawn from each cask and then, mixed and replaced. The same operation is then repeated.
Accordingly, the foregoing operation is performed precisely 2 times.
After the conclusion of the 2nd operation,
precisely 8.875 liters of acid remain in cask P.
Determine the value of x.