<PRE><B>Question 688891</B>
&lt;font face=&quot;Times New Roman&quot; size=&quot;+2&quot;&gt;


600 ounces of 90% copper is 540 ounces of pure copper.  *[tex \LARGE x] ounces of 10% copper is *[tex \LARGE 0.10x] ounces of pure copper.  *[tex \LARGE 600\ +\ x] ounces of 40% copper is *[tex \LARGE 0.40(600\ +\ x)] ounces of pure copper, so:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 0.10x\ +\ 540\ =\ 0.40(600\ +\ x)]


Solve for *[tex \LARGE x]


John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
&lt;font face=&quot;Math1&quot; size=&quot;+2&quot;&gt;Egw to Beta kai to Sigma&lt;/font&gt;
My calculator said it, I believe it, that settles it
&lt;div style=&quot;text-align:center&quot;&gt;&lt;a href=&quot;http://outcampaign.org/&quot; target=&quot;_blank&quot;&gt;&lt;img src=&quot;http://cdn.cloudfiles.mosso.com/c116811/scarlet_A.png&quot; border=&quot;0&quot; alt=&quot;The Out Campaign: Scarlet Letter of Atheism&quot; width=&quot;143&quot; height=&quot;122&quot; /&gt;&lt;/a&gt;&lt;/div&gt;
&lt;/font&gt;</PRE>