document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1057406>Question 1057406</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The current in a stream moves at a speed of 8 km/h.  A boat travels 15 km upstream and 15 km downstream in a total time of 2 hr. What is the speed of the boat in still&#8203; water? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #672492 by </B><A HREF=/tutors/aboutme.mpl?userid=jorel555><B>jorel555(1290)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jorel555><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=672492\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let s be the speed of the boat in still water. Then:<BR>\n" );
document.write( "15/(s+8) + 15/(s-8)=2<BR>\n" );
document.write( "15(s-8)+15(s+8)=2(sē-64)<BR>\n" );
document.write( "2sē-30s-128=0<BR>\n" );
document.write( "sē-15s-64=0<BR>\n" );
document.write( "Using the quadratic formula,  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"s+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, we get two roots of 18.4658560997 and -3.46585609973. Throwing out the negative result, we get the speed of the boat in still water to be 18.47 kph. &#9786;&#9786;&#9786;&#9786; </SPAN>\n" );
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