document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=636940>Question 636940</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I am not sure how to figuere out the answer to these two questions:<BR>\n" );
document.write( "21.) The makimum speed of a barge in still water is 8 miles per hour. At this rate, a 30 mile trip downstream (with the current) takes as much time as an 18 mile trip upstream (against the current).<BR>\n" );
document.write( "A. Find the rational expressions that measure the amount of time it takes for the barge to go downstream and upstream if c represents the speed of the current.<BR>\n" );
document.write( "B. What is the speed of the current?\r<BR>\n" );
document.write( "\n" );
document.write( "Please tell me what I should do on this question.<BR>\n" );
document.write( "Thank you Tim </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #401311 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=401311\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The makimum speed of a barge in still water is 8 miles per hour. At this rate, a 30 mile trip downstream (with the current) takes as much time as an 18 mile trip upstream (against the current).<BR>\n" );
document.write( "A. Find the rational expressions that measure the amount of time it takes for the barge to go downstream and upstream if c represents the speed of the current.<BR>\n" );
document.write( "Downstream DATA:<BR>\n" );
document.write( "distance = 30 miles ; rate = 8+c ; time = 30/(8+c) hrs<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Upstream DATA:<BR>\n" );
document.write( "distance = 18 miles ; rate = 8-c ; time 18/(8-c) hrs<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "time up = time down<BR>\n" );
document.write( "18/(8-c) = 30/(8+c)<BR>\n" );
document.write( "18(8+c) = 30(8-c)<BR>\n" );
document.write( "144 + 18c = 240 - 30c<BR>\n" );
document.write( "48c = 96<BR>\n" );
document.write( "c = 2 mph (speed of the current)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "=================<BR>\n" );
document.write( "B. What is the speed of the current? <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );