document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=201658>Question 201658</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/9780073533490/algebrahomeworkh></A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Filling a tank. A water tank has an inlet pipe and a drain<BR>\n" );
document.write( "pipe. A full tank can be emptied in 30 minutes if the drain<BR>\n" );
document.write( "is opened and an empty tank can be filled in 45 minutes<BR>\n" );
document.write( "with the inlet pipe opened. If both pipes are accidentally<BR>\n" );
document.write( "opened when the tank is full, then how long will it take to<BR>\n" );
document.write( "empty the tank? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #151906 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=151906\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Filling a tank. A water tank has an inlet pipe and a drain<BR>\n" );
document.write( "pipe. A full tank can be emptied in 30 minutes if the drain<BR>\n" );
document.write( "is opened and an empty tank can be filled in 45 minutes<BR>\n" );
document.write( "with the inlet pipe opened. If both pipes are accidentally<BR>\n" );
document.write( "opened when the tank is full, then how long will it take to<BR>\n" );
document.write( "empty the tank?<BR>\n" );
document.write( "--------------------<BR>\n" );
document.write( "Drain Pipe DATA:<BR>\n" );
document.write( "time = 30 min/job ; rate = 1/30 job/min <BR>\n" );
document.write( "-----------------------<BR>\n" );
document.write( "Fill Pipe DATA:<BR>\n" );
document.write( "time = 45 min/job ; rate = 1/45 job/min<BR>\n" );
document.write( "-------------------------<BR>\n" );
document.write( "Together DATA:<BR>\n" );
document.write( "time = x min/job ; rate = 1/x job/min<BR>\n" );
document.write( "--------------------------------------------<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "fill rate - drain rate  = together rate<BR>\n" );
document.write( "1/30 - 1/45 = 1/x<BR>\n" );
document.write( "45x - 30x = 30*45<BR>\n" );
document.write( "15x = 30*45<BR>\n" );
document.write( "x = 2*45<BR>\n" );
document.write( "x = 90 minutes (time for both pipes together to fill the tank)<BR>\n" );
document.write( "===========================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );