document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1005772>Question 1005772</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A man is three eighths of the way across a bridge when he hears a train coming from behind. \r<BR>\n" );
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document.write( "If he runs as fast as possible back toward the train, he will get off the bridge just in time to avoid a collision.\r<BR>\n" );
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document.write( "Also, if he runs as fast as possible away from the train, he will get off the bridge (on the other side) just in time to avoid a collision.\r<BR>\n" );
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document.write( "The train is traveling at 60 miles per hour. How fast does the man run?\r<BR>\n" );
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document.write( "Hi! So I sent this question already, but my email says it didn't send so I apologize if you have already seen it. Thanks for taking the time to help! Also, sorry if there are any typos! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #621980 by </B><A HREF=/tutors/aboutme.mpl?userid=KMST><B>KMST(5328)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=KMST><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=KMST><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=621980\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> THE ALGEBRA-STYLE SOLUTION:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L ALIGN=MIDDLE  ALT=\"L\"   DISABLED_style= \"max-width:90%; height:auto;\" >= length of the bridge, in miles<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%283%2F8%29%2AL ALIGN=MIDDLE  ALT=\"%283%2F8%29%2AL\"   DISABLED_style= \"max-width:90%; height:auto;\" >= distance to cover running towards the train<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L-%283%2F8%29%2AL=%285%2F8%29%2AL ALIGN=MIDDLE  ALT=\"L-%283%2F8%29%2AL=%285%2F8%29%2AL\"   DISABLED_style= \"max-width:90%; height:auto;\" >= distance to cover running away from the train<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x ALIGN=MIDDLE  ALT=\"x\"   DISABLED_style= \"max-width:90%; height:auto;\" >= the man's running speed, in miles per hour<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%283%2F8%29%2AL%2Fx ALIGN=MIDDLE  ALT=\"%283%2F8%29%2AL%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" >= time (in hours) the man must run towards the train to save himself<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%285%2F8%29%2AL%2Fx ALIGN=MIDDLE  ALT=\"%285%2F8%29%2AL%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" >= time (in hours) the man must run away from the train to save himself<BR>\n" );
document.write( "Running toward the train is scarier, but it will save time and effort.<BR>\n" );
document.write( "The time saved, in hours is<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%285%2F8%29%2AL%2Fx-%283%2F8%29%2AL%2Fx=%285%2F8-3%2F8%29%2A%28L%2Fx%29=%282%2F8%29%2A%28L%2Fx%29=L%2F%224+x%22 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" > .<BR>\n" );
document.write( "That is the time the train takes to cover the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L ALIGN=MIDDLE  ALT=\"L\"   DISABLED_style= \"max-width:90%; height:auto;\" > miles from one end of the bridge to the other, at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60 ALIGN=MIDDLE  ALT=\"60\"   DISABLED_style= \"max-width:90%; height:auto;\" > miles per hour:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%2F60 ALIGN=MIDDLE  ALT=\"L%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" > hours.<BR>\n" );
document.write( "So,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%2F%224+x%22=L%2F60 ALIGN=MIDDLE  ALT=\"L%2F%224+x%22=L%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" >--><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F%224+x%22=1%2F60 ALIGN=MIDDLE  ALT=\"1%2F%224+x%22=1%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" >---><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4x=60 ALIGN=MIDDLE  ALT=\"4x=60\"   DISABLED_style= \"max-width:90%; height:auto;\" >---><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=60%2F4 ALIGN=MIDDLE  ALT=\"x=60%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" >---><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28x=15%29 ALIGN=MIDDLE  ALT=\"highlight%28x=15%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > .<BR>\n" );
document.write( " <BR>\n" );
document.write( "NOTE:<BR>\n" );
document.write( "If you do not need to explain step by step, you can start by writing<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%285%2F8%29%2AL%2Fx-%283%2F8%29%2AL%2Fx=L%2F60 ALIGN=MIDDLE  ALT=\"%285%2F8%29%2AL%2Fx-%283%2F8%29%2AL%2Fx=L%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" > .<BR>\n" );
document.write( " <BR>\n" );
document.write( "ANOTHER WAY TO THINK OF IT:<BR>\n" );
document.write( "In the time the man would have run the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F8 ALIGN=MIDDLE  ALT=\"3%2F8\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the bridge towards the train,<BR>\n" );
document.write( "the train will get to the bridge.<BR>\n" );
document.write( "During that time, the man can cover another <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F8 ALIGN=MIDDLE  ALT=\"3%2F8\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the bridge,<BR>\n" );
document.write( "and be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F8+%2B3%2F8=6%2F8=3%2F4 ALIGN=MIDDLE  ALT=\"3%2F8+%2B3%2F8=6%2F8=3%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the way through the bridge.<BR>\n" );
document.write( "While the man runs that remaining <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1-3%2F4=1%2F4 ALIGN=MIDDLE  ALT=\"1-3%2F4=1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the bridge length,<BR>\n" );
document.write( "the train at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60 ALIGN=MIDDLE  ALT=\"60\"   DISABLED_style= \"max-width:90%; height:auto;\" > miles per hour covers the whole span of the bridge.<BR>\n" );
document.write( "Since during the same time the man cover <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the distance covered by the train,<BR>\n" );
document.write( "his speed must be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the speed of the train, or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60mph%2F4=highlight%2815mph%29 ALIGN=MIDDLE  ALT=\"60mph%2F4=highlight%2815mph%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > .<BR>\n" );
document.write( "That is a mental-math, no-need-to-show-your-work way (the one to use for a quick answer for the SAT). </SPAN>\n" );
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