document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=284124>Question 284124</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The Northern Hills swimming pool can be filled by a vent in 10 hours. It can emptied by a drain pipe in 20 hours. The manager mistankely leaves the drain pipe open while trying to fill the pool before memorial day, How long will it take to fill the pool.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #206173 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=206173\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
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document.write( "Working together problems go like this:\r<BR>\n" );
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document.write( "If A can do a job in <i>x</i> time periods, then A can do <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \frac{1}{x}\"> of the job in 1 time period.  Likewise, if B can do the same job in <i>y</i> time periods, then B can do <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \frac{1}{y}\"> of the job in 1 time period.\r<BR>\n" );
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document.write( "So, working together, they can do\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \  \frac{1}{x}\ +\ \frac{1}{y}\ =\ \frac{x\ +\ y}{xy} \">\r<BR>\n" );
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document.write( "of the job in 1 time period.\r<BR>\n" );
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document.write( "Therefore, they can do the whole job in:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \  \frac{1}{\frac{x + y}{xy}}\ =\ \frac{xy}{x\ +\ y}\">\r<BR>\n" );
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document.write( "time periods.\r<BR>\n" );
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document.write( "But you have a problem where you have two things working against one another, so the first calculation becomes:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \  \frac{1}{x}\ -\ \frac{1}{y}\ =\ \frac{y\ -\ x}{xy} \">\r<BR>\n" );
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document.write( "And the second part becomes:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \  \frac{1}{\frac{y - x}{xy}}\ =\ \frac{xy}{y\ -\ x}\">\r<BR>\n" );
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document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi} + 1 = 0\"><BR>\n" );
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