Math
posted by Paul .
A chemistry teacher needs 2.5 liters of a sulfuric acid solution that is 20% sulfuric acid and 80% water . He has 2 liters of a 15% sulfuric acid solutionleft over from earlier laboratory exercises. He also has 44 liters of a 50% solution. Let x represent the number of liters of the 15% solution that can be mixed with Y liters of the 50% solution to make 2.5 liters of the needed 20% solution. Which of the following shows a system of equations that could get the solved to find the amounts of the 15% and 50% solutions that could be mixed to get the required solution?
A) X+Y=2.5
0.15X+0.50Y=0.20
B) x+y=0.20(2.5)
0.15x+0.50y=2.5
C) x+y=2.5
0.15x+0.50y=0.20(2.5)
D)x+y=0.65
x+y=0.20(2.5)

Please check if division signs are missing in some of the answers.
What is your choice, and why?