document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=721106>Question 721106</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An inlet pipe can fill a pool in 3 hours. The outlet pipe takes 12 hours to empty the pool. How long will it take to fill the pool if both pipes are open? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #442207 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=442207\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The work at opposite signs, but their rates still can combine through addition.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Use rates in the form of jobs per unit time.<BR>\n" );
document.write( "Inlet pipe rate is +1/3 pools per hour.<BR>\n" );
document.write( "Outlet pipe rate is -1/12 pools per hour.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Both pipes operating at the same time is of rate <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F3%2B%28-1%2F12%29=1%2F3-1%2F12 ALIGN=MIDDLE  ALT=\"1%2F3%2B%28-1%2F12%29=1%2F3-1%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" > pools per hour.  Rate is positive <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F12=1%2F4 ALIGN=MIDDLE  ALT=\"3%2F12=1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > pools per hour.  This is simply 4 hours to fill the pool. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );