SOLUTION: a chemist needs 130 milliliters of a 79% solution but has only 29% and 94% solutions available. Find how many milliliters of each that should be mixed to get the desired solution.

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: a chemist needs 130 milliliters of a 79% solution but has only 29% and 94% solutions available. Find how many milliliters of each that should be mixed to get the desired solution.       Log On


   



Question 70952: a chemist needs 130 milliliters of a 79% solution but has only 29% and 94% solutions available. Find how many milliliters of each that should be mixed to get the desired solution.

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Let x = the required number of ml of 29% solution and 130-x = the required number of ml of 94% solution to make 130 ml of 79% solution. From this you can write the equation after converting the percentages to their equivalent decimal values:
0.29x + 0.94(130-x) = 0.79(130) Simplify and solve for x.
0.29x + 122.2 - 0.94x = 102.7 Combine like-terms.
-0.65x + 122.2 = 102.7 Subtract 122.2 from both sides.
-0.65x = -19.5 Divide both sides by -0.65
x = 30 and 130-x = 130-30 = 100
The Chemist will require 30 ml of 29% solution and 100 ml of 94% solution.
Check:
0.29(30) + 0.94(100) = 8.7 + 94 = 102.7
0.79(130) = 102.7