document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=96312>Question 96312</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a motor boat can maintain a constant speed of 16 miles per hour relative to the water. The boat makes a trip upstream to a certain point in 20 minutes; the return trip takes 15 minutes. What is the speed of the current? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #70182 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=70182\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a motor boat can maintain a constant speed of 16 miles per hour relative to the water. The boat makes a trip upstream to a certain point in 20 minutes; the return trip takes 15 minutes. What is the speed of the current?<BR>\n" );
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document.write( "Let x = speed of the current<BR>\n" );
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document.write( "(16 + x) = speed downstream<BR>\n" );
document.write( "(16 - x) = speed upstream<BR>\n" );
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document.write( "Convert 20 min to hrs: 20/60 = 1/3 hr<BR>\n" );
document.write( "Convert 15 min to hrs: 15/60 = 1/4 hr<BR>\n" );
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document.write( "We know the distance upstream and distance downstream are equal<BR>\n" );
document.write( "Make a distance equation from that fact:   Dist = time * speed<BR>\n" );
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document.write( "Dist downstream = dist upstream<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+x) = <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-x)<BR>\n" );
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document.write( "Get rid of the denominators, multiply equation by 12, results:<BR>\n" );
document.write( "3(16 + x) =  4(16 - x)<BR>\n" );
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document.write( "48 + 3x = 64 - 4x<BR>\n" );
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document.write( "3x + 4x = 64 - 48<BR>\n" );
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document.write( "7x = 16<BR>\n" );
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document.write( "x = 16/7 is the speed to the current<BR>\n" );
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document.write( "That's about 2.3 mph<BR>\n" );
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document.write( "Check solution by finding the distances<BR>\n" );
document.write( "1/4(16+2.3) = 4.6 mi<BR>\n" );
document.write( "1/3(16-2.3) = 4.6 mi </SPAN>\n" );
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