document.write( "Question 873488: In an alloy of 150 pounds of zinc and copper there are 100 pounds of copper. How much copper must be added so that the alloy may be 10% zinc. \n" ); document.write( "
Algebra.Com's Answer #526921 by ankor@dixie-net.com(22740)\"\" \"About 
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In an alloy of 150 pounds of zinc and copper there are 100 pounds of copper.
\n" ); document.write( " How much copper must be added so that the alloy may be 10% zinc.
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\n" ); document.write( "If there's 100 lb of copper there must be 50 lb zinc, initially
\n" ); document.write( "For a mixture to be 10% zinc, it has to be 90% copper
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\n" ); document.write( "Write a percent copper equation
\n" ); document.write( "100 + x = .90(150+x)
\n" ); document.write( "100 + x = 135 + .9x
\n" ); document.write( "x -.9x = 135 - 100
\n" ); document.write( ".1x = 35
\n" ); document.write( "x = 35/.1
\n" ); document.write( "x = 350 lb of copper required
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\n" ); document.write( "Check this; 350 + 150 = 500 lb resulting mixture of copper & zinc
\n" ); document.write( "Then .10(500) = 50 of zinc, which is the amt of zinc we have.
\n" ); document.write( "And .90(500) = 450 lb of copper \n" ); document.write( "
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