document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=509028>Question 509028</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane, traveling against a 60 km/hr headwind, covers 2100km in the same time that it could travel 2400km with a 70km tailwind. What is the speed of the plane with no headwind or tailwind? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #341243 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><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=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=341243\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let speed of plane = xmph\r<BR>\n" );
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document.write( "time against = time with wind\r<BR>\n" );
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document.write( "time against = 2100/(x-60)<BR>\n" );
document.write( "time with wind = 2400/(x+70)\r<BR>\n" );
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document.write( "2100/(x-60)= 2400/(x+70)\r<BR>\n" );
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document.write( "2100(x+70)=2400(x-60)\r<BR>\n" );
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document.write( "2100x+147000=2400x-144000\r<BR>\n" );
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document.write( "2400x-2100x=147000+144000<BR>\n" );
document.write( "300x=294000<BR>\n" );
document.write( "/300<BR>\n" );
document.write( "x=960 mph </SPAN>\n" );
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