document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=881931>Question 881931</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In a round trip, a plane flies 990 miles each way,one way with tailwind and one with headwind. The total trip time is 3 hours and 20 mins. The airspeed of the plane is 600 miles/hour. What is the speed of the wind?\r<BR>\n" );
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document.write( "To me, this seems extremely bizarre and I am wondering where the heck did the speed of wind come into the question\r<BR>\n" );
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document.write( "In no rush for the answer and thanks in advanced for your help! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #532605 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=532605\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let\r<BR>\n" );
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document.write( "p = speed of plane in still air (without any wind at all)<BR>\n" );
document.write( "w = speed of wind\r<BR>\n" );
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document.write( "The tailwind speeds the plane up (since it's coming from the tail and it's pushing the plane along where it wants to go). So the speed of the plane with a tailwind is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=p%2Bw ALIGN=MIDDLE  ALT=\"p%2Bw\"   DISABLED_style= \"max-width:90%; height:auto;\" > mph.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D+=+r%2At ALIGN=MIDDLE  ALT=\"D+=+r%2At\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D+=+%28p%2Bw%29%2At1 ALIGN=MIDDLE  ALT=\"D+=+%28p%2Bw%29%2At1\"   DISABLED_style= \"max-width:90%; height:auto;\" > Replace r with <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=p%2Bw ALIGN=MIDDLE  ALT=\"p%2Bw\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D+=+%28600%2Bw%29%2At1 ALIGN=MIDDLE  ALT=\"D+=+%28600%2Bw%29%2At1\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=p+=+600 ALIGN=MIDDLE  ALT=\"p+=+600\"   DISABLED_style= \"max-width:90%; height:auto;\" > (the airspeed of the plane)\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=990+=+%28600%2Bw%29%2At1 ALIGN=MIDDLE  ALT=\"990+=+%28600%2Bw%29%2At1\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in the distance d = 990 and solve for t1\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=990%2F%28600%2Bw%29+=+t1 ALIGN=MIDDLE  ALT=\"990%2F%28600%2Bw%29+=+t1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t1+=+990%2F%28600%2Bw%29 ALIGN=MIDDLE  ALT=\"t1+=+990%2F%28600%2Bw%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the time it takes to travel with the tailwind is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t1+=+990%2F%28600%2Bw%29 ALIGN=MIDDLE  ALT=\"t1+=+990%2F%28600%2Bw%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "-------------------------------------------------------\r<BR>\n" );
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document.write( "The headwind slows the plane down (since it's coming from the head and it's going in the opposite direction of the plane). So the speed of the plane with a headwind is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=p-w ALIGN=MIDDLE  ALT=\"p-w\"   DISABLED_style= \"max-width:90%; height:auto;\" > mph.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D+=+%28p-w%29%2At2 ALIGN=MIDDLE  ALT=\"D+=+%28p-w%29%2At2\"   DISABLED_style= \"max-width:90%; height:auto;\" > Replace r with <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=p-w ALIGN=MIDDLE  ALT=\"p-w\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D+=+%28600-w%29%2At2 ALIGN=MIDDLE  ALT=\"D+=+%28600-w%29%2At2\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=p+=+600 ALIGN=MIDDLE  ALT=\"p+=+600\"   DISABLED_style= \"max-width:90%; height:auto;\" > (the airspeed of the plane)\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=990+=+%28600-w%29%2At2 ALIGN=MIDDLE  ALT=\"990+=+%28600-w%29%2At2\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in the distance d = 990 and solve for t2\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=990%2F%28600-w%29+=+t2 ALIGN=MIDDLE  ALT=\"990%2F%28600-w%29+=+t2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t2+=+990%2F%28600-w%29 ALIGN=MIDDLE  ALT=\"t2+=+990%2F%28600-w%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the time it takes to travel with the headwind is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t2+=+990%2F%28600-w%29 ALIGN=MIDDLE  ALT=\"t2+=+990%2F%28600-w%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "-------------------------------------------------------\r<BR>\n" );
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document.write( "The two times t1 and t2 add to \"3 hours, 20 minutes\" which is equivalent to \"3 1/3 hours\" (since 20/60 = 1/3)\r<BR>\n" );
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document.write( "That's equivalent to 10/3 hours (3 + 1/3 = 9/3 + 1/3 = 10/3)\r<BR>\n" );
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document.write( "So...\r<BR>\n" );
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document.write( "which means\r<BR>\n" );
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document.write( "-------------------------------------------------------\r<BR>\n" );
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document.write( "Now let's solve for w\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%28600%2Bw%29%28600-w%29%28990%2F%28600%2Bw%29+%2B+990%2F%28600-w%29%29+=+%2810%2F3%29%2A3%28600%2Bw%29%28600-w%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" > Multiply both sides by the LCD to clear out the fractions.\r<BR>\n" );
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document.write( "So the windspeed is <font color=\"red\">60 miles per hour</font> </SPAN>\n" );
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