document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=600459>Question 600459</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A train running at a uniform speed passes a bridge 275m long in 15 seconds and another bridge 425m long in 21 seconds. Find :<BR>\n" );
document.write( "1. the length of the train:<BR>\n" );
document.write( "2. the speed of the train in km/hr.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #379398 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=379398\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A train running at a uniform speed passes a bridge 275m long in 15 seconds and another bridge 425m long in 21 seconds.<BR>\n" );
document.write( " Find<BR>\n" );
document.write( ":<BR>\n" );
document.write( "1. the length of the train:<BR>\n" );
document.write( "2. the speed of the train in km/hr.<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Let t = length of the train in meters<BR>\n" );
document.write( "Let s = the speed of the train in meters/sec<BR>\n" );
document.write( ":<BR>\n" );
document.write( "write a speed equation for each bridge: Speed = dist/time<BR>\n" );
document.write( ":<BR>\n" );
document.write( "s = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28t%2B275%29%29%2F15 ALIGN=MIDDLE  ALT=\"%28%28t%2B275%29%29%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "s = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28t%2B425%29%29%2F21 ALIGN=MIDDLE  ALT=\"%28%28t%2B425%29%29%2F21\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "therefore<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28t%2B275%29%29%2F15 ALIGN=MIDDLE  ALT=\"%28%28t%2B275%29%29%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28t%2B425%29%29%2F21 ALIGN=MIDDLE  ALT=\"%28%28t%2B425%29%29%2F21\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "Cross multiply<BR>\n" );
document.write( "21(t+275) = 15(t+425)<BR>\n" );
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document.write( "21t + 5775 = 15t + 6375<BR>\n" );
document.write( ":<BR>\n" );
document.write( "21t - 15t = 6375 - 5775<BR>\n" );
document.write( "6t = 600<BR>\n" );
document.write( "t = 100 meters is the length of the train <BR>\n" );
document.write( ":<BR>\n" );
document.write( "Find the speed<BR>\n" );
document.write( "s = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28100%2B275%29%29%2F15 ALIGN=MIDDLE  ALT=\"%28%28100%2B275%29%29%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "s = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=375%2F15 ALIGN=MIDDLE  ALT=\"375%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "s = 25 meter/sec<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Convert to km/hr:<BR>\n" );
document.write( "S = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%283600%2A25%29%29%2F1000 ALIGN=MIDDLE  ALT=\"%28%283600%2A25%29%29%2F1000\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "S = 90 km/hr<BR>\n" );
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