document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=994514>Question 994514</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An airplane flies 410 miles with the wind and 310 against the wind in the same length of time.  If the speed of the wind is 40, what is the speed of the airplane in still air?<BR>\n" );
document.write( "A.). 293mph.   B). 288mph.  C). 124mph.  D). 278mph\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "I have tried this:  \r<BR>\n" );
document.write( "\n" );
document.write( "X=d/t.               <BR>\n" );
document.write( "X=410 -40<BR>\n" );
document.write( "X=370\r<BR>\n" );
document.write( "\n" );
document.write( "X=310+40<BR>\n" );
document.write( "X=350<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #613559 by </B><A HREF=/tutors/aboutme.mpl?userid=macston><B>macston(5194)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=macston><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=macston><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=613559\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
document.write( "t=time; d=distance; r=rate<BR>\n" );
document.write( "t=d/r<BR>\n" );
document.write( ".<BR>\n" );
document.write( "With wind:<BR>\n" );
document.write( "t=410mi/r+40<BR>\n" );
document.write( "Against wind:<BR>\n" );
document.write( "t=310mi/r-40<BR>\n" );
document.write( ".<BR>\n" );
document.write( "Since time in both directions is the same:<BR>\n" );
document.write( "410mi/r+40=310mi/r-40<BR>\n" );
document.write( "410(r-40)=310(r+40)<BR>\n" );
document.write( "410r-16400=310r+12400<BR>\n" );
document.write( "100r=28800<BR>\n" );
document.write( "r=288<BR>\n" );
document.write( ".<BR>\n" );
document.write( "ANSWER: The rate of the plane in still air is 288 mph.\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );