document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=157512>Question 157512</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A boat can go 33 mph in still water. It takes as long to go 300 miles upstream as it does to go downstream 360 miles. How fast is the current?\r<BR>\n" );
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document.write( "Will someone please explain this to me? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #116079 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><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=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=116079\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Sure!<BR>\n" );
document.write( "Distance(d) equals Rate(r) times Time(t) or d=rt;  r=d/t and t=d/r\r<BR>\n" );
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document.write( "Let r=rate (speed ) of the current\r<BR>\n" );
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document.write( "Time to travel upstream=300/(33-r) {note: when we go against the current we must subtract the rate of the current)<BR>\n" );
document.write( "Time to travel downstream=360/(33+r) (note: downstream we add the rate of the current)\r<BR>\n" );
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document.write( "Now we are told that the above two times are the same, so:\r<BR>\n" );
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document.write( "300/(33-r)=360/(33+r)  multiply each side by (33-r)(33+r) (or cross-multiply)<BR>\n" );
document.write( "300(33+r)=360(33-r)  divide each side by 60 (I did this just to reduce the size of the numbers that we have to deal with)<BR>\n" );
document.write( "5(33+r)=6(33-r)  get rid of parens<BR>\n" );
document.write( "165+5r=198-6r subtract 165 from and add 6r to both sides<BR>\n" );
document.write( "165-165+5r+6r=198-165-6r+6r  collect like terms<BR>\n" );
document.write( "11r=33  divide each side by 11<BR>\n" );
document.write( "r=3 mph---------------------------------------speed of the current\r<BR>\n" );
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document.write( "CK<BR>\n" );
document.write( "300/(33-3)=360/(33+3)<BR>\n" );
document.write( "300/30=360/36<BR>\n" );
document.write( "10=10\r<BR>\n" );
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document.write( "Hope this helps---ptaylor </SPAN>\n" );
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