SOLUTION: You have 80 ml of a 85% alcohol solution. How many mls of a 15% solution must be added to make a 40% solution?

Question 981444: You have 80 ml of a 85% alcohol solution. How many mls of a 15% solution must be added to make a 40% solution?
Found 2 solutions by macston, josmiceli:
Answer by macston(5194) (Show Source): You can put this solution on YOUR website!
.
Let x=ml of 15% solution
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(0.85)(80ml)+(0.15)x=(0.40)(x+80ml)
68ml+0.15x=0.40x+32ml Subtract 32 ml from each side.
36ml+0.15x=0.40x Subtract 0.15x from each side.
36ml=0.25x Multiply each side by 4.
144ml=x
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = ml of 15% solution needed
= ml of alcohol in 15% solution
ml of alcohol in 85% solution
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144 ml of 15% solution are needed
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check:

OK
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