A chemist is preparing a mixture using two solutions, Solution A and Solution B. Solution A contains 20% acid, and Solution B contains 50% acid. The chemist mixes liters of Solution A and liters of Solution B to obtain a total of 10 liters of pure acid. The equation represents this situation. Which is the best interpretation of in this context?
The total volume of Solution B used
The percentage of acid in Solution B
The total volume of pure acid contributed by Solution B
The total volume of the final mixture
