document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=939724>Question 939724</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A boat travels 45 kms. upstream and then returns to the dock traveling 45 kilometers downstream. The speed of the boat in still water is 12 km/hr. The total time for the trip is 8 hours. Find the speed of the current.\r<BR>\n" );
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document.write( "I got the answer to be the current = 3 km/hr. Is this correct?<BR>\n" );
document.write( "Thank you! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #572673 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=572673\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A boat travels 45 kms. upstream and then returns to the dock traveling 45 kilometers downstream. The speed of the boat in still water is 12 km/hr. The total time for the trip is 8 hours. Find the speed of the current. <BR>\n" );
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document.write( "let c=speed of current<BR>\n" );
document.write( "12+c=speed of boat downstream<BR>\n" );
document.write( "12-c=speed of boat upstream<BR>\n" );
document.write( "Travel time=distance/speed<BR>\n" );
document.write( "..<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=45%2F%2812%2Bc%29%2B45%2F%2812-c%29=8 ALIGN=MIDDLE  ALT=\"45%2F%2812%2Bc%29%2B45%2F%2812-c%29=8\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "lcd:(12-c)(12+c)<BR>\n" );
document.write( "45(12-c)+45(12+c)=8(12-c)(12+c)<BR>\n" );
document.write( "540-45c+540+45c=8(12^2-c^2)<BR>\n" );
document.write( "1080=8(144-c^2)<BR>\n" );
document.write( "1080=1152-8c^2<BR>\n" );
document.write( "8c^2=72<BR>\n" );
document.write( "c^2=9<BR>\n" );
document.write( "c=3<BR>\n" );
document.write( "speed of current=3 km/hr<BR>\n" );
document.write( "congratulations! You got it right. </SPAN>\n" );
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