document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=371782>Question 371782</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A pilot can fly a plane at 150 mph in calm air. A recent trip of 400 mi flying with the wind and 400 mi returning against the wind took 6 h. Find the rate of the wind. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #264846 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=264846\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A pilot can fly a plane at 150 mph in calm air. A recent trip of 400 mi flying with the wind and 400 mi returning against the wind took 6 h. Find the rate of the wind.\r<BR>\n" );
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document.write( "let speed of wind be x mph<BR>\n" );
document.write( "speed of plane = 150 mph<BR>\n" );
document.write( "..<BR>\n" );
document.write( "against wind speed = 150-x<BR>\n" );
document.write( "with wind speed = 150 +x<BR>\n" );
document.write( "..<BR>\n" );
document.write( "distance = 400 miles.<BR>\n" );
document.write( "time with wind + time against wind = 6 hours<BR>\n" );
document.write( "..<BR>\n" );
document.write( "t = d/r<BR>\n" );
document.write( "400/(150-x)+400/(150+x) =6<BR>\n" );
document.write( "400(150+x)+400(150-x)/(150-x)(150+x) = 6<BR>\n" );
document.write( "60000+400x+60000-400x= 6(150^2-x^2)<BR>\n" );
document.write( "120,000=22500-6x^2<BR>\n" );
document.write( "6x^2= 135000-120000<BR>\n" );
document.write( "6x^2=15000<BR>\n" );
document.write( "x^2=2500<BR>\n" );
document.write( "x= 50 mph rate of wind<BR>\n" );
document.write( "m.ananth@hotmail.ca </SPAN>\n" );
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