SOLUTION: A chemist needs to mix 20 liters of 40% salt solution with some 70% solution to get a mixture that is 50% salt. How many liters of 70% solution should be used?

Question 147292: A chemist needs to mix 20 liters of 40% salt solution with some 70% solution to get a mixture that is 50% salt. How many liters of 70% solution should be used?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
In words:
(amount of salt you end up with) / (total amount of solution) = % salt
Let = amount of 70% solution to be added
How much salt is in the 20 liters of 40% solution?
liters
How much salt is in the 70% solution?

How much total solution do you end up with?

So, the equation to use is:

multiply both sides by

The chemist needs to add 10 liters of the 70% solution
check answer:

OK
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