document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=388652>Question 388652</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 19.   A motorboat can go 16 miles downstream on a river in 20 minutes. It takes 30 minutes for this boat to go back upstream the same 16 miles.Let x = the speed of the boat.<BR>\n" );
document.write( "Let y = the speed of the current.\r<BR>\n" );
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document.write( "a. Write an equation for the motion of the motorboat downstream. <BR>\n" );
document.write( "b. Write an equation for the motion of the motorboat upstream. <BR>\n" );
document.write( "c. Find the speed of the current. \r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #275005 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=275005\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A motorboat can go 16 miles downstream on a river in 20 minutes. It takes 30 minutes for this boat to go back upstream the same 16 miles.Let x = the speed of the boat.<BR>\n" );
document.write( "Let y = the speed of the current.\r<BR>\n" );
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document.write( "a. Write an equation for the motion of the motorboat downstream.<BR>\n" );
document.write( "d = 48t, d in miles, t in hours<BR>\n" );
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document.write( "b. Write an equation for the motion of the motorboat upstream.<BR>\n" );
document.write( "d = 32t, d in miles, t in hours<BR>\n" );
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document.write( "c. Find the speed of the current. <BR>\n" );
document.write( "y = 8 mph<BR>\n" );
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document.write( "16 miles in 20 mins = 48 mph<BR>\n" );
document.write( "16 miles in 30 mins = 32 mph<BR>\n" );
document.write( "The boat speed is the average = (48 + 32)/2 = 40 mph<BR>\n" );
document.write( "The current is the difference = 8 mph<BR>\n" );
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