<PRE><B>Question 1158713</B>
&lt;br&gt;
Common sense should tell us that, since 15% is halfway between 10% and 20%, the mixture should use equal amounts of the 10% and 20% solutions.&lt;br&gt;
ANSWER: 17.5 mL of each&lt;br&gt;
Algebraically, if required....&lt;br&gt;
x = mL of 10% solution
35-x = mL of 20% solution&lt;br&gt;
The total amount in the two ingredients is 15% of the total 35 mL:&lt;br&gt;
{{{.10(x)+.20(35-x) = .15(35)}}}&lt;br&gt;
Solve using basic algebra; of course your answer should be 17.5 mL of each.&lt;br&gt;
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