document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1114311>Question 1114311</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A student group flies to Cancun for spring break, a distance of 1200 miles. The plane used for both trips has an average cruising speed of 300 miles per hour in still air. The trip down is with the prevailing winds and takes 1 1/2 hours less than the trip back, against the same strength wind. What is the wind speed? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #837931 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=837931\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> distance of 1200 miles\r<BR>\n" );
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document.write( "plane speed = 300 mph in still air\r<BR>\n" );
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document.write( "The trip down is with the prevailing winds and takes 1 1/2 hours less than the trip back,\r<BR>\n" );
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document.write( "Trip down takes less time so plane flies with wind\r<BR>\n" );
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document.write( "Return against wind\r<BR>\n" );
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document.write( "down - speed = 300 +x<BR>\n" );
document.write( "time taken = 1200/(300+x)\r<BR>\n" );
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document.write( "return speed = 300-x<BR>\n" );
document.write( "time taken = 1200/(300-x)\r<BR>\n" );
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document.write( "Return time - down time = 1.5 hours\r<BR>\n" );
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document.write( "((1200(300+x))-(1200*(300-x))/((300+x)(300-x)))=1.5\r<BR>\n" );
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document.write( "360000+1200x -360000+1200x/(90000-x^2)=1.5\r<BR>\n" );
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document.write( "2400x= 1.5(90000-x^2)\r<BR>\n" );
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document.write( "2400x = 135000-1.5x2\r<BR>\n" );
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document.write( "1.5x^2+2400x -135000=0\r<BR>\n" );
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document.write( "solve <BR>\n" );
document.write( "x= 54.4 mph  wind speed\r<BR>\n" );
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document.write( "Check<BR>\n" );
document.write( "(1200/(300-54.4))- (1200/(354.4))=1.49999<BR>\n" );
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