document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1067837>Question 1067837</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Flying to Berlin with a tailwind, a plane averages 174 km/h.  On the return trip, the plane averages 132 km/h while flying back into the same wind.  find the speed of the wind and the speed of the plane in still air. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #683016 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52781)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=683016\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
document.write( "Flying to Berlin with a tailwind, a plane averages 174 km/h.  On the return trip, the plane averages 132 km/h while flying back <BR>\n" );
document.write( "into the same wind.  find the speed of the wind and the speed of the plane in still air.<BR>\n" );
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document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
document.write( "Let u be the plane speed at no wind (in km/h).\r\n" );
document.write( "Let v be the wind speed.\r\n" );
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document.write( "Then the speed of the plane with the wind is u+v km/h.\r\n" );
document.write( "     The speed against the wind is u-v km/h.\r\n" );
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document.write( "The condition says\r\n" );
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document.write( "u + v = 174,\r\n" );
document.write( "u - v = 132.\r\n" );
document.write( "----------------- Add the two equations.\r\n" );
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document.write( "2u    = 174 + 132 = 306   --->  u = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=306%2F2 ALIGN=MIDDLE  ALT=\"306%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 153 km/h  speed of the plane at no wind.\r\n" );
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document.write( "Now, from (1) v = 174-153 = 21 km/h is speed of wind.\r\n" );
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document.write( "Solved.\r<BR>\n" );
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document.write( "It is a typical \"tailwind and headwind\" word problem.\r<BR>\n" );
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document.write( "See the lessons \r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=http://www.algebra.com/algebra/homework/word/travel/Wind-and-Current-problems.lesson>Wind and Current problems</A> \r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&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> \r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/word/travel/Selected-problems-from-the-archive-on-a-plane-flying-with-and-against-the-wind.lesson>Selected problems from the archive on a plane flying with and against the wind</A> \r<BR>\n" );
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document.write( "in this site.\r<BR>\n" );
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document.write( "In these lessons you will find the detailed solutions of many similar problems. \r<BR>\n" );
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document.write( "Read them attentively.\r<BR>\n" );
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document.write( "In this way you will learn how to solve similar problems once and for all.\r<BR>\n" );
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document.write( "Also, you have this free of charge online textbook in ALGEBRA-I in this site\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.\r<BR>\n" );
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document.write( "The referred lessons are the part of this textbook under the section \"<U>Word problems</U>\", the topic \"<U>Travel and Distance problems</U>\".\r<BR>\n" );
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document.write( " </SPAN>\n" );
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