document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=820133>Question 820133</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two trains leave two cities that are 310 km apart, traveling toward each other on parallel tracks. One train travels at 70 kph and the other travels at 90 kph. If the slower train leaves at 9:40 a.m. and the faster train leaves at 11:00 a.m., at what time will they pass each other? Round the answer to the nearest minute. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #493422 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=493422\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The time of the slower train's head start is<BR>\n" );
document.write( "11:00 AM minus 9:40 AM = 1 hour 20 minutes<BR>\n" );
document.write( "------------<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d%5B1%5D+ ALIGN=MIDDLE  ALT=\"+d%5B1%5D+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the slower train's head start in km<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d%5B1%5D+=+70%2A1.333+ ALIGN=MIDDLE  ALT=\"+d%5B1%5D+=+70%2A1.333+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d%5B1%5D+=+93.331+ ALIGN=MIDDLE  ALT=\"+d%5B1%5D+=+93.331+\"   DISABLED_style= \"max-width:90%; height:auto;\" > km<BR>\n" );
document.write( "--------------------<BR>\n" );
document.write( "Start a stopwatch when the faster train leaves<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+ ALIGN=MIDDLE  ALT=\"+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the time on the stopwatch when <BR>\n" );
document.write( "the trains meet<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+ ALIGN=MIDDLE  ALT=\"+d+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the distance that the faster train travels<BR>\n" );
document.write( "until they meet<BR>\n" );
document.write( "---------------<BR>\n" );
document.write( "Faster train's equation:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+70t+ ALIGN=MIDDLE  ALT=\"+d+=+70t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Slower train's equation:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+310+-+93.331+-+d+=+90t+ ALIGN=MIDDLE  ALT=\"+310+-+93.331+-+d+=+90t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Substitute (1) into (2)<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+216.669+-+70t+=+90t+ ALIGN=MIDDLE  ALT=\"+216.669+-+70t+=+90t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+160t+=+216.669+ ALIGN=MIDDLE  ALT=\"+160t+=+216.669+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+1.354+ ALIGN=MIDDLE  ALT=\"+t+=+1.354+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "This is the time after 11:00 AM when they meet<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+.354%2A60+=+21.25+ ALIGN=MIDDLE  ALT=\"+.354%2A60+=+21.25+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "--------------------<BR>\n" );
document.write( "They will meet at about 12:21 PM<BR>\n" );
document.write( "-----------<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+70t+ ALIGN=MIDDLE  ALT=\"+d+=+70t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+70%2A1.354+ ALIGN=MIDDLE  ALT=\"+d+=+70%2A1.354+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+94.78+ ALIGN=MIDDLE  ALT=\"+d+=+94.78+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+310+-+93.331+-+d+=+90t+ ALIGN=MIDDLE  ALT=\"+310+-+93.331+-+d+=+90t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+310+-+93.331+-+d+=+90%2A1.354+ ALIGN=MIDDLE  ALT=\"+310+-+93.331+-+d+=+90%2A1.354+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+216.669+-+d+=+121.86+ ALIGN=MIDDLE  ALT=\"+216.669+-+d+=+121.86+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+216.669+-+121.86+ ALIGN=MIDDLE  ALT=\"+d+=+216.669+-+121.86+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+94.81+ ALIGN=MIDDLE  ALT=\"+d+=+94.81+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "error may be due to rounding off\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "  <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );