document.write( "Question 1116842: A pilot can fly a plane at 125 mph in calm air. A recent trip of 300 mi flying with the wind and 300 mi returning against the wind took 5 h. Find the rate of the wind. \n" ); document.write( "

Algebra.Com's Answer #731754 by ikleyn(52906) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "The \"time\" equation is\r\n" );
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document.write( " +  = 5    hours.    (1)\r\n" );
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document.write( "Solve for w, the rate of wind.\r\n" );
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document.write( "Answer.  Rate of wind is 25 miles per hour.\r\n" );
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\n" ); document.write( "\n" ); document.write( "I solved it mentally (since the answer is OBVIOUS). // The formal solution is as follows.\r
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document.write( "    Multiply both sides of (1) by (125+w)*(125-w). You will get\r\n" );
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document.write( "    300*(125-w) + 300*(125+w) = 5*(125-w)*(125+w)\r\n" );
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document.write( "    60*(125-w) + 60*(125+w) = (125-w)*(125+w)\r\n" );
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document.write( "    2*60*125 = \r\n" );
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document.write( "     =  = 125*(125-120) = 125*5 = .\r\n" );
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document.write( "    w =  = 25.\r\n" );
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document.write( "    Check.   +  =  +  = 3 + 2 = 5  hours.   ! Correct !\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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\n" ); document.write( "It is a typical \"tailwind and headwind\" word problem.\r
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\n" ); document.write( "\n" ); document.write( "See the lessons \r
\n" ); document.write( "\n" ); document.write( "    - Wind and Current problems \r
\n" ); document.write( "\n" ); document.write( "    - Wind and Current problems solvable by quadratic equations \r
\n" ); document.write( "\n" ); document.write( "    - Selected problems from the archive on a plane flying with and against the wind \r
\n" ); document.write( "\n" ); document.write( "in this site.\r
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\n" ); document.write( "\n" ); document.write( "Also, you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this textbook under the section \"Word problems\", the topic \"Travel and Distance problems\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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