document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=255405>Question 255405</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a freight train leaves a station traveling 60 miles per hour. thirty minutes later a passenger train leaves the station in the same direction on a parallel track at a speed of 72 miles per hour. How long will it take the passenger train to catch the freight train? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #187668 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=187668\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Imagine you have a stopwatch and you start it when<BR>\n" );
document.write( "the 2nd train leaves. You are all-knowing and powerful,<BR>\n" );
document.write( "and can stop the stopwatch when the trains meet.<BR>\n" );
document.write( "How far has the 1st train gone when you start the stopwatch?<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d+=+r%2At ALIGN=MIDDLE  ALT=\"d+=+r%2At\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+60 ALIGN=MIDDLE  ALT=\"r+=+60\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi/hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+1%2F2 ALIGN=MIDDLE  ALT=\"t+=+1%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d+=+60%2A%281%2F2%29 ALIGN=MIDDLE  ALT=\"d+=+60%2A%281%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d+=+30 ALIGN=MIDDLE  ALT=\"d+=+30\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "Now the 2 train will travel different distances but for the same time<BR>\n" );
document.write( "on the stopwatch (<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5B1%5D+=+t%5B2%5D ALIGN=MIDDLE  ALT=\"t%5B1%5D+=+t%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >)<BR>\n" );
document.write( "For the 2nd train:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B2%5D+=+r%5B2%5D%2At%5B2%5D ALIGN=MIDDLE  ALT=\"d%5B2%5D+=+r%5B2%5D%2At%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5B2%5D+=+72 ALIGN=MIDDLE  ALT=\"r%5B2%5D+=+72\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi/hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B2%5D+=+72%2At%5B2%5D ALIGN=MIDDLE  ALT=\"d%5B2%5D+=+72%2At%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The 1st train has <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30 ALIGN=MIDDLE  ALT=\"30\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi less to travel<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B2%5D+-+30+=+60%2At%5B2%5D ALIGN=MIDDLE  ALT=\"d%5B2%5D+-+30+=+60%2At%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B2%5D+=+60%2At%5B2%5D+%2B+30 ALIGN=MIDDLE  ALT=\"d%5B2%5D+=+60%2At%5B2%5D+%2B+30\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Use <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B2%5D ALIGN=MIDDLE  ALT=\"d%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > in the 1st equation for <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B2%5D ALIGN=MIDDLE  ALT=\"d%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > in the 2nd equation<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=72%2At%5B2%5D+=+60%2At%5B2%5D+%2B+30 ALIGN=MIDDLE  ALT=\"72%2At%5B2%5D+=+60%2At%5B2%5D+%2B+30\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=12%2At%5B2%5D+=+30 ALIGN=MIDDLE  ALT=\"12%2At%5B2%5D+=+30\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5B2%5D+=+2.5 ALIGN=MIDDLE  ALT=\"t%5B2%5D+=+2.5\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "It will take the passenger train 2.5 hrs to catch the freight train<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "The 1st train has traveled for <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2.5+%2B+.5+=+3 ALIGN=MIDDLE  ALT=\"2.5+%2B+.5+=+3\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B1%5D+=+60%2A3 ALIGN=MIDDLE  ALT=\"d%5B1%5D+=+60%2A3\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B1%5D+=+180 ALIGN=MIDDLE  ALT=\"d%5B1%5D+=+180\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "And the 2nd train's distance is<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B2%5D+=+72%2A2.5 ALIGN=MIDDLE  ALT=\"d%5B2%5D+=+72%2A2.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5B2%5D+=+180 ALIGN=MIDDLE  ALT=\"d%5B2%5D+=+180\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "These are the TOTAL distances the trains must travel<BR>\n" );
document.write( "and they are equal as they must be when they meet<BR>\n" );
document.write( " <BR>\n" );
document.write( "   </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );