document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=642107>Question 642107</A>: <I><SPAN STYLE=\"word-break: break-all;\"> bob takes escalator from subway to street level. if he runs-up 8 stairs it takes him 46.5 seconds. if he runs-up 13 stairs it takes him 39.0 seconds. \r<BR>\n" );
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document.write( "How long will it take bob to get to the top if he doesn't run at all? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #404177 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=404177\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  bob takes escalator from subway to street level. <BR>\n" );
document.write( " if he runs-up 8 stairs it takes him 46.5 seconds.<BR>\n" );
document.write( " if he runs-up 13 stairs it takes him 39.0 seconds.<BR>\n" );
document.write( "How long will it take bob to get to the top if he doesn't run at all?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "let s = no. of steps traveled by the escalator<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(s+8) = no. of steps when he runs up in 46.5 sec<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(s+13) = no. of steps when he runs up in 39 sec<BR>\n" );
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document.write( "Let d = total distance traveled by the escalator<BR>\n" );
document.write( "then<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F%28%28s%2B8%29%29%29 ALIGN=MIDDLE  ALT=\"d%2F%28%28s%2B8%29%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 46.5<BR>\n" );
document.write( "d = 46.5(s+8)<BR>\n" );
document.write( "and<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F%28%28s%2B13%29%29 ALIGN=MIDDLE  ALT=\"d%2F%28%28s%2B13%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 39<BR>\n" );
document.write( "d = 39(s+13)<BR>\n" );
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document.write( "d=d, therefore we can combine the equations<BR>\n" );
document.write( "46.5(s+8) = 39(s+13)<BR>\n" );
document.write( "46.5s + 372 = 39s + 507<BR>\n" );
document.write( "46.5s - 39s = 507 - 372<BR>\n" );
document.write( "7.5s = 135<BR>\n" );
document.write( "s = 135/7.5<BR>\n" );
document.write( "s = 18 steps<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Find the time (t) when just letting escalator move<BR>\n" );
document.write( "Time varies inversely with speed<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%2F39 ALIGN=MIDDLE  ALT=\"t%2F39\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2818%2B13%29%2F18 ALIGN=MIDDLE  ALT=\"%2818%2B13%29%2F18\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%2F39 ALIGN=MIDDLE  ALT=\"t%2F39\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=31%2F18 ALIGN=MIDDLE  ALT=\"31%2F18\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "cross multiply<BR>\n" );
document.write( "18t = 39 * 31<BR>\n" );
document.write( "18t = 1209<BR>\n" );
document.write( "t = 1209/18<BR>\n" );
document.write( "t = 67.2 seconds if he just ride it\r<BR>\n" );
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document.write( " <BR>\n" );
document.write( " </SPAN>\n" );
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