If 20 ounces of a strong vinegar solution are diluted with 40 ounces of water to form a five-percent vinegar solution, what was the concentration of the original solution?  Select:
A) 8%
B) 10%
C) 12%
D) 15%
E) 18%
Let x be the concentration of the original solution.   20x = 0.05(60)   x = 0.15   The answer is 15%.
<result>D</result>
If 20 ounces of a strong vinegar solution are diluted with 40 ounces of water to form a five-percent vinegar solution, what was the concentration of the original solution?