Question 605692: how many liters of a 30% acid solution must be mixed with 2 liters of a 12% solution to obtain a 15% solution Answer by mathie123(224) (Show Source):
You can put this solution on YOUR website! For a word problem, the first step is to determine what it is we are trying to solve for. In most cases, once we figure this out we can give it a variable and using the question make an equation using that variable.
In our case, we are trying to solve for the number of litres of the 30% solution. Let's call this x.
Using the question, we can write the following equation:
(This is because we have x litres of 30% solution, adding that to 2 litres of 10% solution should give us x+2 litres of 15% solution-- if this is unclear please email me and I can help you further:) )
So now all that is left to do is solve for x:
This means that there needs to be approximately 4.29 litres of the 30% acid solution mixed.
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