document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1169435>Question 1169435</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An express train is 50 kph faster than the freight train. If it takes 2 hour less for the express train to travel 600 km as compare to the freight train, how fast is the express train? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #794202 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=794202\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> distance=v*t<BR>\n" );
document.write( "v=freight and it takes t hours so the speed is 600/t<BR>\n" );
document.write( "for the express it takes 600/(t-2) hours<BR>\n" );
document.write( "600/(t-2)-50=600/t<BR>\n" );
document.write( "multiply by t(t-2)<BR>\n" );
document.write( "600t-50t^2+100t=600t-1200<BR>\n" );
document.write( "0=50t^2-100t-1200<BR>\n" );
document.write( "0=t^2-2t-24=(t-6)(t+4)<BR>\n" );
document.write( "only positive root is t=6 hours<BR>\n" );
document.write( "so the the velocity for the express train is 100 kph and the express is 150 kph and takes 4 hours, 2 hours fewer, to go the same distance. </SPAN>\n" );
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