Question 1049054
In the lab, Lashonda has two solutions that contain alcohol and is mixing them with each other. She uses 4 times as much Solution A as Solution B. Solution A is 13% alcohol and Solution B is 18% alcohol. How many milliliters of Solution B does she use, if the resulting mixture has 350 milliliters of pure alcohol? 
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A = 4B or B = A/4
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0.13A + 0.18B = 350ml
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Substitute for "A" and solve for "B"::

0.13*4B + 0.18B = 350
0.52B + 0.18B = 350
0.7B = 350
B = 35000/7
B = 5000 ml = 5 litres (amt. of solution B needed)
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Cheers,
Stan H.
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