document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=217996>Question 217996</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a twin-engined air craft can fly 1200 miles from city a to city b in 5 hours with the wind and make the return trip in 8 hours against the wind. What is the speed of the wind?\r<BR>\n" );
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document.write( "be sure to define unknowns, set up a system of equations to solve and answer the question being asked. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #164250 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=164250\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a twin-engined air craft can fly 1200 miles from city a to city b in 5 hours with the wind and make the return trip in 8 hours against the wind. What is the speed of the wind? <BR>\n" );
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document.write( "A to B DATA:<BR>\n" );
document.write( "distance = 1200 miles ; time = 5 hrs. ; rate = d/t = 1200/5 = 240 mph<BR>\n" );
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document.write( "B to A DATA:<BR>\n" );
document.write( "distance = 1200 miles ; time = 8 hrs. ; rate = d/t = 1200/8 = 150 mph<BR>\n" );
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document.write( "Equations:<BR>\n" );
document.write( "p + w = 240 mph<BR>\n" );
document.write( "p - w = 150<BR>\n" );
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document.write( "Add the two equations and solve for \"p\":<BR>\n" );
document.write( "2p = 390<BR>\n" );
document.write( "p = 195 mph (speed of the plane in still air)<BR>\n" );
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document.write( "Substitute into p+w=240 to solve for \"w\";<BR>\n" );
document.write( "195 + w = 240<BR>\n" );
document.write( "w = 45 mph (speed of the wind)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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