document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=898499>Question 898499</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A girl walks down a moving subway escalator. It takes her one minute to go from the street level to the subway platform. If she has walked twice as fast as before, it would take her 45 seconds to go down. How long will it take her standing on the escalator? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #545032 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=545032\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A girl walks down a moving subway escalator.<BR>\n" );
document.write( " It takes her one minute to go from the street level to the subway platform.<BR>\n" );
document.write( " If she has walked twice as fast as before, it would take her 45 seconds to go down.<BR>\n" );
document.write( " How long will it take her standing on the escalator?<BR>\n" );
document.write( "let d the length of the escalator in ft<BR>\n" );
document.write( "let s = effective speed the first time<BR>\n" );
document.write( "then<BR>\n" );
document.write( "2s = effective speed the 2nd time<BR>\n" );
document.write( "let x = the speed of the escalator<BR>\n" );
document.write( ":<BR>\n" );
document.write( "1st scenario<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F%28%28s%2Bx%29%29 ALIGN=MIDDLE  ALT=\"d%2F%28%28s%2Bx%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 60 sec<BR>\n" );
document.write( "d = 60(s+x)<BR>\n" );
document.write( "2nd scenario<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F%28%282s%2Bx%29%29 ALIGN=MIDDLE  ALT=\"d%2F%28%282s%2Bx%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 45 sec<BR>\n" );
document.write( "d=d, therefore<BR>\n" );
document.write( "60(s+x) = 45(2s+x)<BR>\n" );
document.write( "simplify divide by 15<BR>\n" );
document.write( "4(s+x) = 3(2s+x)<BR>\n" );
document.write( "4s + 4x = 6s + 3x<BR>\n" );
document.write( "4x - 3x = 6s - 4s<BR>\n" );
document.write( "x = 2s, the speed of the escalator<BR>\n" );
document.write( ":<BR>\n" );
document.write( "To find s, let's assume the d = 180 ft<BR>\n" );
document.write( "60(s+2s) = 180<BR>\n" );
document.write( "60(3s) = 180<BR>\n" );
document.write( "180s = 180<BR>\n" );
document.write( "s = 1 ft/sec<BR>\n" );
document.write( ":<BR>\n" );
document.write( "we know the escalator is 2s, or 2 ft/sec<BR>\n" );
document.write( "Find the time it takes just standing on the escalator<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=180%2F2 ALIGN=MIDDLE  ALT=\"180%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 90 seconds<BR>\n" );
document.write( ":<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Confirm this, the 2nd run is 4s or 4 ft/sec<BR>\n" );
document.write( "180/4 = 45 sec </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );