document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=993541>Question 993541</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a motorboat maintained a constant speed of 15 miles per hour relative to the water in going 10 miles upstream and then returning. The total time for the trip was 1.5 hours. use this information to find the speed of the current.  </SPAN>\n" );
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document.write( "A motorboat maintained a constant speed of 15 miles per hour relative to the water in going 10 miles upstream and then returning. The total time for the trip was 1.5 hours. use this information to find the speed of the current.<BR>\n" );
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document.write( "Let &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v ALIGN=MIDDLE  ALT=\"v\"   DISABLED_style= \"max-width:90%; height:auto;\" >&nbsp; be the unknown current speed of the river in  miles per hour.<BR>\n" );
document.write( "When the motorboat moves upstream, &nbsp;its speed relative to the bank of the river is &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15-v ALIGN=MIDDLE  ALT=\"15-v\"   DISABLED_style= \"max-width:90%; height:auto;\" >&nbsp; miles per hour, &nbsp;and the time spent moving upstream is &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10%2F%2815-v%29 ALIGN=MIDDLE  ALT=\"10%2F%2815-v%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > &nbsp;hours. \r<BR>\n" );
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document.write( "When the motorboat moves downstream, &nbsp;its speed relative to the bank of the river is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15%2Bv ALIGN=MIDDLE  ALT=\"15%2Bv\"   DISABLED_style= \"max-width:90%; height:auto;\" > &nbsp;miles per hour, &nbsp;and the time spent moving downstream is &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10%2F%2815%2Bv%29 ALIGN=MIDDLE  ALT=\"10%2F%2815%2Bv%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > &nbsp;hours. \r<BR>\n" );
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document.write( "So, &nbsp;the total time upstream and downstream is &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10%2F%2815-v%29+%2B+10%2F%2815%2Bv%29 ALIGN=MIDDLE  ALT=\"10%2F%2815-v%29+%2B+10%2F%2815%2Bv%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, &nbsp;and it is equal to &nbsp;1.5&nbsp; hours, &nbsp;according to the problem's input.<BR>\n" );
document.write( "This gives an equation &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10%2F%2815-v%29 ALIGN=MIDDLE  ALT=\"10%2F%2815-v%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10%2F%2815%2Bv%29 ALIGN=MIDDLE  ALT=\"10%2F%2815%2Bv%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1.5 ALIGN=MIDDLE  ALT=\"1.5\"   DISABLED_style= \"max-width:90%; height:auto;\" >. <BR>\n" );
document.write( "To simplify the equation, &nbsp;multiply both sides by &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2815-v%29%2A%2815%2Bv%29 ALIGN=MIDDLE  ALT=\"%2815-v%29%2A%2815%2Bv%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > &nbsp;and collect like terms. &nbsp;Step by step, &nbsp;you get <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10%2815%2Bv%29+%2B+10%2815-v%29+=+1.5%2A%2815-v%29%2815%2Bv%29 ALIGN=MIDDLE  ALT=\"10%2815%2Bv%29+%2B+10%2815-v%29+=+1.5%2A%2815-v%29%2815%2Bv%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300 ALIGN=MIDDLE  ALT=\"300\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1.5%2A%2815%5E2-v%5E2%29 ALIGN=MIDDLE  ALT=\"1.5%2A%2815%5E2-v%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=200 ALIGN=MIDDLE  ALT=\"200\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15%5E2-v%5E2 ALIGN=MIDDLE  ALT=\"15%5E2-v%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > &nbsp;&nbsp;&nbsp;&nbsp;(after dividing both sides by 1.5),<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%5E2 ALIGN=MIDDLE  ALT=\"v%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=225+-+200 ALIGN=MIDDLE  ALT=\"225+-+200\"   DISABLED_style= \"max-width:90%; height:auto;\" >,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%5E2 ALIGN=MIDDLE  ALT=\"v%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=25 ALIGN=MIDDLE  ALT=\"25\"   DISABLED_style= \"max-width:90%; height:auto;\" >,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v ALIGN=MIDDLE  ALT=\"v\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5 ALIGN=MIDDLE  ALT=\"5\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<U>Answer</U>. &nbsp;The speed of the current is &nbsp;5&nbsp; miles per hour.\r<BR>\n" );
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document.write( "For more similar problems see the lesson &nbsp;<A  rel=nofollow HREF=http://www.algebra.com/algebra/homework/word/travel/Wind-and-Current-problems-solvable-by-quadratic-equations.lesson>Wind and Current problems solvable by quadratic equations</A>&nbsp; in this site.\r<BR>\n" );
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document.write( "It is free of charge and without registration. \r<BR>\n" );
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