SOLUTION: A scientist has 50 mL of a 50% acid solution and wishes to create a 20% acid solution by adding a quantity of a 10% acid solution. How many milliliters of the 20% acid solution wil

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A scientist has 50 mL of a 50% acid solution and wishes to create a 20% acid solution by adding a quantity of a 10% acid solution. How many milliliters of the 20% acid solution wil      Log On


   

Question 604184: A scientist has 50 mL of a 50% acid solution and wishes to create a 20% acid solution by adding a quantity of a 10% acid solution. How many milliliters of the 20% acid solution will she have after she mixes the weaker and stronger solutions? Write and solve a linear system. Use substitution or elimination methods to solve.
Answer by alicealc(293) About Me  (Show Source):
You can put this solution on YOUR website!
Let the volume of 10% acid solution is x ml

50 * 50% + x * 10% = (50 + x)*20%
(omit the % sign)
2500 + 10x = (50+x)*20
2500 + 10x = 1000 + 20x
2500 - 1000 = 20x - 10x
1500 = 10x
x = 1500/10 = 150

so, in the end she will have 50+150 = 200 ml of 20% acid solution