SOLUTION: In the lab, Ann has two solutions that contain alcohol and is mixing them with each other. Solution A is 10% alcohol and Solution B is 60% alcohol. She uses 300 milliliters of So

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Question 1121590: In the lab, Ann has two solutions that contain alcohol and is mixing them with each other. Solution A is 10% alcohol and Solution B is 60% alcohol. She uses 300 milliliters of Solution A. How many milliliters of Solution B does she use, if the resulting mixture is a 30% alcohol solution?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
300 ml of 10% is 30 ml alcohol
x ml of 60% is .60x alcohol
The total volume is 300+x and the alcohol 30%, so the pure alcohol is .3(300+x) or 90+0.3x
That is the sum of the two above, so 30+.60x=90+0.3x
0.3x=60 ml
x=200 ml Solution B
Can check in that .10 to .60 is .5, and .30 is 2/5 of the way, closer to .10 than to .6
300 of .10 outweighs the 200 of .60 and puts it 3/5 from .60 or 2/5 of the way from .10