SOLUTION: A pharmacist needs 500 milliliters of a 10% phenorbarbital solution. She only has 5% and 25% solutions available. How many milliliters of each solution should she mix to obtain th

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: A pharmacist needs 500 milliliters of a 10% phenorbarbital solution. She only has 5% and 25% solutions available. How many milliliters of each solution should she mix to obtain th      Log On


   

Question 390889: A pharmacist needs 500 milliliters of a 10% phenorbarbital solution. She only has 5% and 25% solutions available. How many milliliters of each solution should she mix to obtain the desired solution?

Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
0.05*x + 0.25*(500 - x) = 0.10*500;
0.05x + 125 - 0.25x = 50;
-0.20x = -75;
x = 375 milliliters of the 5% solution, and
500 - x = 125 milliliters of the 25% solution.