document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=166418>Question 166418</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 84.)Gone Fishing. Debbie traveled by boat 5 miles upstream to fish in her favorite spot. Because of the 4 - mph current, it took her 20 minutes longer to get there than to return. how fast will her boat go in still water? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #122703 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=122703\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 84.)Gone Fishing. Debbie traveled by boat 5 miles upstream to fish in her favorite spot. Because of the 4 - mph current, it took her 20 minutes longer to get there than to return. how fast will her boat go in still water?<BR>\n" );
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document.write( "time = distance/speed<BR>\n" );
document.write( "time upstream = 5/(b - 4)  b is the boat's speed<BR>\n" );
document.write( "time downstream = 5/(b+4) = time upstream - 1/3  (20 mins is 1/3 hours)<BR>\n" );
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document.write( "5/(b+4) = 5/(b-4) - 1/3<BR>\n" );
document.write( "Multiply by 3*(b+4)*(b-4)<BR>\n" );
document.write( "15*(b-4) = 15*(b+4) - b^2 + 16<BR>\n" );
document.write( "15b-60 = 15b+ 60 -b^2 + 16<BR>\n" );
document.write( "-60 = 76 - b^2<BR>\n" );
document.write( "b^2 = 136<BR>\n" );
document.write( "b = 11.66 mph\r<BR>\n" );
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document.write( " </SPAN>\n" );
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