document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=266575>Question 266575</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A motorboat can maintain a constant speed of 16 miles per hour relative to the water.  The boat makes a trip upstrem to a certain point in 20 minutes, the return trip takes 15 minutes.  What is the speed of the current?<BR>\n" );
document.write( "Thanks for any help you can provide,<BR>\n" );
document.write( "orchidia@tampabay.rr.com<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 #195982 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=195982\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A motorboat can maintain a constant speed of 16 miles per hour relative to the water. <BR>\n" );
document.write( "The boat makes a trip upstream to a certain point in 20 minutes, the return trip takes 15 minutes. <BR>\n" );
document.write( "What is the speed of the current?<BR>\n" );
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document.write( "Change 20 min to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F3 ALIGN=MIDDLE  ALT=\"1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr<BR>\n" );
document.write( "Change 15 min to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr<BR>\n" );
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document.write( "Let c = rate of the current<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(16-c) = rate upstream<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(16+c) = rate downstream<BR>\n" );
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document.write( "Assume the trip up and the trip back were the same distance<BR>\n" );
document.write( "Write a distance equation: dist = time * rate<BR>\n" );
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document.write( "Dist upstream = dist downstream<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" >(16+c) = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F3 ALIGN=MIDDLE  ALT=\"1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" >(16-c)<BR>\n" );
document.write( "Multiply both sides by 12, to get rid of the denominators, results:<BR>\n" );
document.write( "3(16+c) = 4(16-c)<BR>\n" );
document.write( "48 + 3c = 64 - 4c<BR>\n" );
document.write( "3c + 4c = 64 - 48<BR>\n" );
document.write( "7c = 16<BR>\n" );
document.write( "c = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=16%2F7 ALIGN=MIDDLE  ALT=\"16%2F7\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "c = 2.2857 mph is the current<BR>\n" );
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document.write( "Check solution by finding the distance of each trip (should be equal)<BR>\n" );
document.write( ".25(16+2.2857) = 4.57 mi<BR>\n" );
document.write( ".333(16-2.2857) = 4.57 mi </SPAN>\n" );
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