document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1054744>Question 1054744</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An inlet pipe on a swimming pool can be used to fill the pool in 21 hours. The drain pipe can be used to empty the pool in 28 hours. If the pool is 1/2 filled and then the inlet pipe and drain pipe are opened, how long from that time will it take to fill the pool?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #669944 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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/cgi-bin/show-face.mpl?user=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=669944\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> An inlet pipe on a swimming pool can be used to fill the pool in 21 hours. The drain pipe can be used to empty the pool in 28 hours. If the pool is 1/2 filled and then the inlet pipe and drain pipe are opened, how long from that time will it take to fill the pool?<BR>\n" );
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document.write( "The inlet fills 1/21 pool per hour.<BR>\n" );
document.write( "The drain fills -1/28 per hour.<BR>\n" );
document.write( "Together --> 1/21 - 1/28 pools per hour.<BR>\n" );
document.write( "= 1/84 pools per hour.<BR>\n" );
document.write( "--> 84 hours to fill it from empty.<BR>\n" );
document.write( "Starting at 1/2 full --> 42 hours. </SPAN>\n" );
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