document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1200756>Question 1200756</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane can travel 1,015 miles in 7 hours traveling against the wind. Traveling with the same wind, the plane can travel 820 miles in 4 hours. How fast can the plane travel in still air and how fast is the wind current? \r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #834965 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=834965\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "The speed against the wind is 1015/7 = 145 mph; the speed with the wind is 820/4 = 205 mph.<br><BR>\n" );
document.write( "Tutor @ikleyn has shown a standard formal algebraic method for getting from there to finding the speed of the plane and the speed of the wind.<br><BR>\n" );
document.write( "For a quick informal path to the answer (if formal algebra is not required), recognize that the 205 mph is the speed of the plane PLUS the speed of the wind, while the 145 mph is the speed of the plane MINUS the speed of the wind.<br><BR>\n" );
document.write( "Logically that means the speed of the plane is halfway between 205 mph and 145mph, which is 175 mph; then the speed of the wind is the difference between 175 mph and 205 mph (or between 175 mph and 145 mph).<br><BR>\n" );
document.write( "ANSWERS: plane speed 175 mph; wind speed 30 mph<br><BR>\n" );
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