document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=184163>Question 184163</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane flies 900km with a tail wind in 3 hours. The same plane takes 4 hours to make the return trip against the wind. What is 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 #138193 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><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=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=138193\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "Distance(d) equals Rate(r) times Time(t) or d=rt;  r=d/t and t=d/r<BR>\n" );
document.write( "Let r=speed of the plane in still air<BR>\n" );
document.write( "Let s=speed of the wind\r<BR>\n" );
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document.write( "If the plane is flying with the wind, we add the wind speed;<BR>\n" );
document.write( "Against the wind, we subtract.  So:<BR>\n" );
document.write( "r+s=900/3=300------------------------------eq1<BR>\n" );
document.write( "r-s=900/4=225------------------------------eq2\r<BR>\n" );
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document.write( "add eq1 and eq2:<BR>\n" );
document.write( "2r=525<BR>\n" );
document.write( "r=262.5 mph---------------------speed of plane in still air<BR>\n" );
document.write( "substitute r=262.5 mph into eq1:<BR>\n" );
document.write( "262.5+s=300<BR>\n" );
document.write( "s=300-262.5=37.5 mph-------------speed of the wind\r<BR>\n" );
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document.write( "Hope this helps---ptaylor </SPAN>\n" );
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