document.write( "Question 1065217: Flying against the wind, a jet travels 5670mi in 7 hours. Flying with the wind, the same jet travels 11,790mi in 9 hours. What is the rate of the jet in still air and what is the rate of the wind?
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Algebra.Com's Answer #680335 by ikleyn(52798) $\"\"$ $\"About$

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\n" ); document.write( "Flying against the wind, a jet travels 5670 mi in 7 hours. Flying with the wind, the same jet travels 11,790 mi in 9 hours.
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document.write( "Let u be the speed of the plane at no wind (in mph),\r\n" );
document.write( "and \"v\" be the speed of the wind.\r\n" );
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document.write( "Then\r\n" );
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document.write( " = u - v    (1)   (speed flying with the wind)\r\n" );
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document.write( " = u + v   (2)   (speed flying against the wind)\r\n" );
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document.write( "Simplify:\r\n" );
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document.write( "u - v =  810,           (1')\r\n" );
document.write( "u + v = 1310.           (2')\r\n" );
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document.write( "Add the two equations (1') and (2'). You will get\r\n" );
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document.write( "2u = 2120  ---->  u =  = 1060 mph.\r\n" );
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document.write( "Then from (2') v = 1310 - u = 1310 - 1060 = 250 mph.\r\n" );
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document.write( "Thus the formal answer is: the speed of the plane is 1060 mph, the speed of wind is 250 mph.\r\n" );
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document.write( "     Now, the speed of wind of 250 mph is more that a strongest hurricane,\r\n" );
document.write( "          so I don't know who invented this problem.\r\n" );
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\n" ); document.write( "\n" ); document.write( "As well as I don't know for whom I solved it and for what.\r
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\n" ); document.write( "\n" ); document.write( "Usually I have good advises for people who come to the forum with similar problems,\r
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