Question 1154729
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You should know how to solve problems like this using a formal algebraic method, such as the one shown by the other tutor.<br>
If an algebraic solution is not required, here is a fast and easy way to solve two-part mixture problems like this:<br>
(1) The target 40% is "twice as close" to 30% as it is to 60%.
(2) Therefore, the mixture must contain twice as much of the 30% ingredient as the 60% ingredient.<br>
Twice as much of the 30% as the 60%, and a total of 60 liters, means 40 liters of the 30% acid solution and 20 liters of the 60% acid solution.<br>
ANSWER: 40 liters of the 30% acid; 20 liters of the 60% acid.<br>
Here is another way to look at the same solution method.<br>
Think of starting with 30% acid and adding 60% acid until the mixture is 40% acid.<br>
You started at 30% and moved towards 60%, stopping when you reached 40%.<br>
40% is one-third of the way from 30% to 60%.<br>
Therefore, 1/3 of the mixture is the 60% acid you are adding.<br>
ANSWER: 1/3 of 60 liters, or 20 liters, of the 60% acid solution; the other 40 liters are the 30% solution.<br>