document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=291185>Question 291185</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The inlet pipe of an oil tank can fill the tank in 1 hour, 30 minutes. The outlet pipe can empty the tank in 1 hour. Find how long it takes to empty the full tank if both pipes are open. Show work. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #210624 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><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=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=210624\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I will deal in minutes<BR>\n" );
document.write( "Let x= time it takes to empty the full tank if both pipes are open<BR>\n" );
document.write( "Then with both pipes open, the tank empties at the rate of 1/x tank per min<BR>\n" );
document.write( "Inlet pipe fills at the rate of 1/90 tank per min<BR>\n" );
document.write( "outlet pipe empties at the rate of 1/60 tank per min<BR>\n" );
document.write( "So with both pipes open the tank empties at the rate of 1/60-1/90 tank per min<BR>\n" );
document.write( "So:<BR>\n" );
document.write( "1/60-1/90=1/x  multiply each term by 180x<BR>\n" );
document.write( "3x-2x=180<BR>\n" );
document.write( "x=180 min or 3 hr-------time it takes to empty the full tank if both pipes are open<BR>\n" );
document.write( "CK<BR>\n" );
document.write( "In 180 min, inlet pipe fills(1/90)*180=2 tanks<BR>\n" );
document.write( "In 180 min, outlet pipe empties (1/60)*180=3 tanks<BR>\n" );
document.write( "so, 3-2=1 tank emptied\r<BR>\n" );
document.write( "\n" );
document.write( "Hope this helps---ptaylor </SPAN>\n" );
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