document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=889870>Question 889870</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane can fly 310 mph in still air. If it can fly 180 miles downwind in the same amount of time it can fly 130 miles upwind, find the velocity 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 #538497 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=538497\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A plane can fly 310 mph in still air. If it can fly 180 miles downwind in the same amount of time it can fly 130 miles upwind, find the velocity of the wind.<BR>\n" );
document.write( "----------<BR>\n" );
document.write( "Downwid DATA:<BR>\n" );
document.write( "distance = 180 miles ; rate = (310+w) mph ; time = 180/(310+w) hrs<BR>\n" );
document.write( "----------<BR>\n" );
document.write( "Upwind DATA:<BR>\n" );
document.write( "distance = 130 miles ; rate = (310-w) mph ; time = 130/(310-w) hrs<BR>\n" );
document.write( "--------------------<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "time up = time down<BR>\n" );
document.write( "130/(310-w) = 180/(310+w)<BR>\n" );
document.write( "--------<BR>\n" );
document.write( "130(310+w) = 180(310-w)<BR>\n" );
document.write( "13*310 + 13w = 18*310 - 18w<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "31w = 5*310<BR>\n" );
document.write( "w = 5*10 = 50 mph (rate of the wind)<BR>\n" );
document.write( "-----------------------------------------<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "------------------<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );