SOLUTION: Hi, I would really appreciate some assistance with this problem: A chemist mixes an 11% acid solution with a 4% acid solution. How many milliliters of each solution must he u

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Question 47403: Hi,
I would really appreciate some assistance with this problem:
A chemist mixes an 11% acid solution with a 4% acid solution. How many milliliters of each solution must he use to get 700 milliliters of a 6% solution?
Thanks,
Louis
Answer by Earlsdon(6294) (Show Source):
You can put this solution on YOUR website!
Let x = the number of ml of the 11% acid solution. The chemist needs to add this to (700-x) ml of the 4% acid solution to get 700 ml of 6% acid solution.
Write the equation, but first change the percents to their decimal equivalents:
0.11x + 0.04(700-x) = 0.06(700) Simplify and solve for x.
0.11x + 28 - 0.04x = 42 Collect like-terms.
0.07x + 28 = 42 Subtract 28 from both sides of the equation.
0.07x = 14 Divide both sides by 0.07
x = 200
700-x = 500
The chemist needs to mix 200 ml of the 11% acid solution with 500 ml of the 4% acid solution to obtain 700 ml of 6% acid solution.