document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=115098>Question 115098</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A BOAT TRAVELS 52 MILES UP THE RIVER IN THE SAME AOUNT OF TIME IT TAKES TO TRAVEL 92 MILES DOWN THE SAME RIVER. IF THE CURRENT IS 5 MILES PER HOUR, WHAT IS THE SPEED OF THE BOAT IN STILL WATER ? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #83733 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=83733\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> HEY! Ease up on the ALL CAPS.\r<BR>\n" );
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document.write( "Remember the formula for distance, rate, and time:  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d=rt ALIGN=MIDDLE  ALT=\"d=rt\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "We want to find the boat's speed through the water, so lets call that r.\r<BR>\n" );
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document.write( "The boat goes up river against the current, so the speed relative to the land is 5 miles per hour less than the speed through the water, or r - 5.\r<BR>\n" );
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document.write( "The boat goes down river with the current, so the speed is 5 mph more, or r + 5.\r<BR>\n" );
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document.write( "First let's rearrange the formula so that it is in terms of time:  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=d%2Fr ALIGN=MIDDLE  ALT=\"t=d%2Fr\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "The amount of time the boat traveled up river is then given by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=52%2F%28r-5%29 ALIGN=MIDDLE  ALT=\"52%2F%28r-5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > and the time down river is given by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=92%2F%28r%2B5%29 ALIGN=MIDDLE  ALT=\"92%2F%28r%2B5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.  And we know from the problem statement that these two times are equal, so:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=92%2F%28r%2B5%29=52%2F%28r-5%29 ALIGN=MIDDLE  ALT=\"92%2F%28r%2B5%29=52%2F%28r-5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=92%28r-5%29=52%28r%2B5%29 ALIGN=MIDDLE  ALT=\"92%28r-5%29=52%28r%2B5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, Cross-multiply the proportion\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=92r-460=52r%2B260 ALIGN=MIDDLE  ALT=\"92r-460=52r%2B260\"   DISABLED_style= \"max-width:90%; height:auto;\" >, Distribute\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=92r-52r=260%2B460 ALIGN=MIDDLE  ALT=\"92r-52r=260%2B460\"   DISABLED_style= \"max-width:90%; height:auto;\" >, Collect like terms<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=40r=720 ALIGN=MIDDLE  ALT=\"40r=720\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r=18 ALIGN=MIDDLE  ALT=\"r=18\"   DISABLED_style= \"max-width:90%; height:auto;\" >, Divide by 40\r<BR>\n" );
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document.write( "And the speed of the boat through the water is 18 miles per hour.\r<BR>\n" );
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document.write( "Last step, VERY important:  Check your answer.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=52%2F%2818-5%29=52%2F13=4 ALIGN=MIDDLE  ALT=\"52%2F%2818-5%29=52%2F13=4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=92%2F%2818%2B5%29=92%2F23=4 ALIGN=MIDDLE  ALT=\"92%2F%2818%2B5%29=92%2F23=4\"   DISABLED_style= \"max-width:90%; height:auto;\" >  Since both times (4 hours) are equal, the answer checks.\r<BR>\n" );
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document.write( "Hope that helps,<BR>\n" );
document.write( "John </SPAN>\n" );
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