document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1170177>Question 1170177</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A cruise ship going across a lake 15km wide travels a distance of 6km at a certain<BR>\n" );
document.write( "speed and then finishes the trip at a speed 1 kph slower than its original speed. The<BR>\n" );
document.write( "boat arrives 20 minutes later than if the original speed is maintained throughout the<BR>\n" );
document.write( "trip. What is the original speed of the cruise ship?<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 #795038 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=795038\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A cruise ship going across a lake 15km wide travels a distance of 6km at a certain speed and then finishes the trip at a speed 1 kph slower than its original speed.<BR>\n" );
document.write( " The boat arrives 20 minutes later than if the original speed is maintained throughout the trip. <BR>\n" );
document.write( "What is the original speed of the cruise ship?<BR>\n" );
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document.write( "let s = original speed<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(s-1) = slower speed<BR>\n" );
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document.write( "Change 20 min to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F3 ALIGN=MIDDLE  ALT=\"1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr<BR>\n" );
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document.write( "Total dist was 15 km therefore he traveled 6 km at s and 9 km at (s-1)<BR>\n" );
document.write( "Find the actual time take for the trip<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=6%2Fs ALIGN=MIDDLE  ALT=\"6%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=9%2F%28%28s-1%29%29 ALIGN=MIDDLE  ALT=\"9%2F%28%28s-1%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%286%28s-1%29%2B9s%29%2F%28s%28s-1%29%29 ALIGN=MIDDLE  ALT=\"%286%28s-1%29%2B9s%29%2F%28s%28s-1%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%286s-6%2B9s%29%2F%28s%28s-1%29%29 ALIGN=MIDDLE  ALT=\"%286s-6%2B9s%29%2F%28s%28s-1%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2815s-6%29%2F%28s%28s-1%29%29 ALIGN=MIDDLE  ALT=\"%2815s-6%29%2F%28s%28s-1%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "then<BR>\n" );
document.write( "actual time - normal time = 1/3 hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2815s-6%29%2F%28s%28s-1%29%29 ALIGN=MIDDLE  ALT=\"%2815s-6%29%2F%28s%28s-1%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15%2Fs ALIGN=MIDDLE  ALT=\"15%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F3 ALIGN=MIDDLE  ALT=\"1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "multiply by 3s(s-1), get rid of the denominators<BR>\n" );
document.write( "3(15s-6) - 15(3(s-1)) = s(s-1)<BR>\n" );
document.write( "45s - 18 - 45s + 45 = s^2 - s<BR>\n" );
document.write( "27 = s^2 - s<BR>\n" );
document.write( "A quadratic equation<BR>\n" );
document.write( "s^2 - s - 27 = 0<BR>\n" );
document.write( "using the quadratic formula, the positive solution<BR>\n" );
document.write( "s = 5.72 km/h is the normal speed<BR>\n" );
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document.write( "seems like we deserve to get an integer here, check in time equation with calc<BR>\n" );
document.write( "(<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=6%2F5.72 ALIGN=MIDDLE  ALT=\"6%2F5.72\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=9%2F4.72 ALIGN=MIDDLE  ALT=\"9%2F4.72\"   DISABLED_style= \"max-width:90%; height:auto;\" >) - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15%2F5.72 ALIGN=MIDDLE  ALT=\"15%2F5.72\"   DISABLED_style= \"max-width:90%; height:auto;\" > =<BR>\n" );
document.write( "1.049  + 1.907 - 2.622 = .334 which is about 1/3 hr or 20 min<BR>\n" );
document.write( "seems to check out, if you find that I screwed this up, let me know. ankor@att.net  </SPAN>\n" );
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