document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=683899>Question 683899</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Good day! I get confused with word problems like this, can you lease help me?\r<BR>\n" );
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document.write( "A boat can travel 48 km downstream in the same time it can travel 32 km upstream.  If the rate of the boat in still water is 20 km/hr, find the rate of the current.\r<BR>\n" );
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document.write( "Thank you so much! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #423811 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=423811\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Hi. This type of problem has basically the same<BR>\n" );
document.write( "setup for solution.<BR>\n" );
document.write( "First, go to things they're looking for, and give it a name.<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+ ALIGN=MIDDLE  ALT=\"+c+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the rate of the current in  km/hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+20+%2B+c+ ALIGN=MIDDLE  ALT=\"+20+%2B+c+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = rate of boat going downstream in km/hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+20+-+c+ ALIGN=MIDDLE  ALT=\"+20+-+c+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = rate of boat going upstream in km/hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+ ALIGN=MIDDLE  ALT=\"+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = time in hrs for both trips<BR>\n" );
document.write( "----------------------------<BR>\n" );
document.write( "Equation for going downstream:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+48+=+%28+20+%2B+c+%29%2At+ ALIGN=MIDDLE  ALT=\"+48+=+%28+20+%2B+c+%29%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Equation for going upstream:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+32+=+%28+20+-+c+%29%2At+ ALIGN=MIDDLE  ALT=\"+32+=+%28+20+-+c+%29%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "There are 2 equations and 2 unknowns, so it's solvable<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+48+%2F+%28+20+%2B+c+%29+ ALIGN=MIDDLE  ALT=\"+t+=+48+%2F+%28+20+%2B+c+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Substitute (1) into (2)<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+32+=+%28+20+-+c+%29%2A%28+48+%2F+%28+20+%2B+c+%29+%29+ ALIGN=MIDDLE  ALT=\"+32+=+%28+20+-+c+%29%2A%28+48+%2F+%28+20+%2B+c+%29+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+32%2A%28+20+%2B+c+%29+=+48%2A%28+20+-+c+%29+ ALIGN=MIDDLE  ALT=\"+32%2A%28+20+%2B+c+%29+=+48%2A%28+20+-+c+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+640+%2B+32c+=+960+-+48c+ ALIGN=MIDDLE  ALT=\"+640+%2B+32c+=+960+-+48c+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+80c+=+960+-+640+ ALIGN=MIDDLE  ALT=\"+80c+=+960+-+640+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+80c+=+320+ ALIGN=MIDDLE  ALT=\"+80c+=+320+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+4+ ALIGN=MIDDLE  ALT=\"+c+=+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The rate of the current is 4 km/hr<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+48+=+%28+20+%2B+4+%29%2At+ ALIGN=MIDDLE  ALT=\"+48+=+%28+20+%2B+4+%29%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+48+=+24t+ ALIGN=MIDDLE  ALT=\"+48+=+24t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+2+ ALIGN=MIDDLE  ALT=\"+t+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+32+=+%28+20+-+4+%29%2At+ ALIGN=MIDDLE  ALT=\"+32+=+%28+20+-+4+%29%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+32+=+16t+ ALIGN=MIDDLE  ALT=\"+32+=+16t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+2+ ALIGN=MIDDLE  ALT=\"+t+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK\r<BR>\n" );
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document.write( " </SPAN>\n" );
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