A chemist needs 10 liters of a 25% acid solution. The solution is to be mixed from

Question:

A chemist needs 10 liters of a 25% acid solution. The solution is to be mixed from three solutions whose concentrations are 10%, 20%, and 50%. How many liters of each solution will satisfy each condition?
(a) Use 2 liters of the 50% solution.
(b) Use as little as possible of the 50% solution.
(c) Use as much as possible of the 50% solution.