document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=897072>Question 897072</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The density and strength of concrete are determined by the ratio of cement and aggregate. Suppose that a contractor has 480ft^3 of a dry concrete mixture that is 70% sand by volume. How much pure sand must be added to form a new mixture that is 75% sand by volume? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #544794 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39617)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=544794\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Available, 480 cubic feet concrete mix at 70% sand.\r<BR>\n" );
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document.write( "A mixture is wanted which is 75% sand.  How much sand to add to the available material?\r<BR>\n" );
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document.write( "Let s = volume of sand to add.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28%28480%2A70%2Bs%29%2F%28480%2Bs%29=75%29 ALIGN=MIDDLE  ALT=\"highlight_green%28%28480%2A70%2Bs%29%2F%28480%2Bs%29=75%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Solve for s.<BR>\n" );
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