document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=451983>Question 451983</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane has a speed of 840 km/h in still air. It can travel 3120 km with the wind in the same time it would take to travel 1920 km against the wind. Find the speed 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 #311409 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=311409\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A plane has a speed of 840 km/h in still air. It can travel 3120 km with the wind in the same time it would take to travel 1920 km against the wind. Find the speed of the wind.<BR>\n" );
document.write( "..<BR>\n" );
document.write( "let x=speed of wind<BR>\n" );
document.write( "(840+x)=speed of plane with wind<BR>\n" );
document.write( "(840-x)=speed of plane against wind<BR>\n" );
document.write( "Travel time = distance/speed (same with and against the wind)<BR>\n" );
document.write( "3120/(840+x)=1920/(840-x)<BR>\n" );
document.write( "cross-multiply<BR>\n" );
document.write( "3120*840-3120x=1920*840+1920x<BR>\n" );
document.write( "3120*840-1920*840=1920x+3120x<BR>\n" );
document.write( "5040x=1008000<BR>\n" );
document.write( "x=200 km/hr<BR>\n" );
document.write( "ans:<BR>\n" );
document.write( "Speed of wind=200 km/hr\r<BR>\n" );
document.write( "\n" );
document.write( "comment: This is a pretty strong wind speed, but I have doubled check my answer and this is what I got </SPAN>\n" );
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