.
Let W be the volume of water to be evaporated.
The amount of the pure antifreeze in the original mixture is 0.65*17 qt.
The volume of the mixture after evaporating water is (17 - W) qt.
The new concentration equation is
= 0.85. (1)
To solve it, multiply both sides by (17-W). You will get
0.65*17 = 0.85*(17-W).
From the equation,
W = = 4.
ANSWER. 4 qt of water must be evaporated.
To check the answer, substitute the found value W= 4 into the basic equation (1).
Solved.
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It is one of typical mixture problems.
There is a bunch of introductory lessons in this site, covering various types of mixture problems
- Mixture problems
- More Mixture problems
- Solving typical word problems on mixtures for solutions
- Word problems on mixtures for antifreeze solutions (*)
- Word problems on mixtures for alloys
- Typical word problems on mixtures from the archive
Especially the lesson marked (*) in this list, contains very similar solved problems.
Read the lessons and become an expert in solution the mixture word problems.
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Mixture problems".
Save the link to this online textbook together with its description
Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson
to your archive and use it when it is needed.