SOLUTION: A scientist mixes water (containing no salt) with a solution that contains 30% salt. She wants to obtain 210 ounces of a mixture that is 15% salt. How many ounces of water and h

Question 1057134: A scientist mixes water (containing no salt) with a solution that contains
30% salt. She wants to obtain 210 ounces of a mixture that is 15%
salt. How many ounces of water and how many ounces of the 30% salt solution should she use?
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617)   (Show Source): You can put this solution on YOUR website!
using just one variable for a two-part mixture problem

The way that tutor ikleyn responded is just like what the video posted/linked above would show, so these are both now examples of how to do such a two-part mixture problem using one single variable.
Answer by ikleyn(52786)   (Show Source): You can put this solution on YOUR website!
.
A scientist mixes water (containing no salt) with a solution that contains
30% salt. She wants to obtain 210 ounces of a mixture
that is 15% salt. How many ounces of water and how many ounces of the 30% salt solution should she use?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Let W = the volume of water to be mixed in ounces). Then the volume of the 30% salt solution needed is (210-W). The balance equation for the salt mass is 0.3*(210-W) = 0.15*210. Simplify and solve for W: 63 - 0.3W = 31.5, 63 - 31.5 = 0.3W, 0.3W = 31.5, W = = 105. Answer. 105 ounces of water is needed.

There is entire bunch of the lessons 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
in this site.

Read them 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 textbook in the section "Word problems" under the topic "Mixture problems".

The textbook contains many other solved word problems, as well as many other interesting and useful things.

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