document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=573698>Question 573698</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A cyclist rides 600 meters up a hill and 400 meters down the other side. his speed is twice as fast downhill as uphill and the whhole journey takes 4 minutes. how long does it take him to reach the summit?\r<BR>\n" );
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document.write( "My working out \r<BR>\n" );
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document.write( "Distance over time= speed so the total journey is 1000 meters and the total time is 4 minutes(240 seconds) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #368833 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=368833\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+ ALIGN=MIDDLE  ALT=\"+s+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = his speed going uphill ( m/min )<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2s+ ALIGN=MIDDLE  ALT=\"+2s+\"   DISABLED_style= \"max-width:90%; height:auto;\" >= his speed going downhill ( m/min )<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;\" > = His time going up hill ( min )<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+4+-+t+ ALIGN=MIDDLE  ALT=\"+4+-+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = his time going downhill ( min )<BR>\n" );
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document.write( "uphill:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+600+=+s%2At+ ALIGN=MIDDLE  ALT=\"+600+=+s%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "downhill:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+400+=+2s%2A%28+4+-+t+%29+ ALIGN=MIDDLE  ALT=\"+400+=+2s%2A%28+4+-+t+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+600%2Ft+ ALIGN=MIDDLE  ALT=\"+s+=+600%2Ft+\"   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=+400+=+2%2A%28+600%2Ft+%29%2A%284+-+t+%29+ ALIGN=MIDDLE  ALT=\"+400+=+2%2A%28+600%2Ft+%29%2A%284+-+t+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+400+=+%28+8+-+2t+%29%2A%28600%2Ft%29+ ALIGN=MIDDLE  ALT=\"+400+=+%28+8+-+2t+%29%2A%28600%2Ft%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+400+=+4800%2Ft+-+1200+ ALIGN=MIDDLE  ALT=\"+400+=+4800%2Ft+-+1200+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+400t+=+4800+-+1200t+ ALIGN=MIDDLE  ALT=\"+400t+=+4800+-+1200t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1600t+=+4800+ ALIGN=MIDDLE  ALT=\"+1600t+=+4800+\"   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+=+3+ ALIGN=MIDDLE  ALT=\"+t+=+3+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "It takes him 3 minutes to reach the summit<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+600%2Ft+ ALIGN=MIDDLE  ALT=\"+s+=+600%2Ft+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+600%2F3+ ALIGN=MIDDLE  ALT=\"+s+=+600%2F3+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+200+ ALIGN=MIDDLE  ALT=\"+s+=+200+\"   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=+400+=+2s%2A%28+4+-+t+%29+ ALIGN=MIDDLE  ALT=\"+400+=+2s%2A%28+4+-+t+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+400+=+2%2A200%2A%28+4+-+3+%29+ ALIGN=MIDDLE  ALT=\"+400+=+2%2A200%2A%28+4+-+3+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+400+=+400+ ALIGN=MIDDLE  ALT=\"+400+=+400+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );