document.write( "Question 90057: A six-passenger plane cruises at 180mph in calm air. If the plane flies 7 miles with the wind in the same amount of time as it flies 5 miles against the wind, then what is the wind speed? \n" ); document.write( "
Algebra.Com's Answer #65387 by stanbon(75887)\"\" \"About 
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six-passenger plane cruises at 180mph in calm air. If the plane flies 7 miles with the wind in the same amount of time as it flies 5 miles against the wind, then what is the wind speed?
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\n" ); document.write( "Let wind speed be \"x mph\"
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\n" ); document.write( "With the wind DATA:
\n" ); document.write( "Distance = 7 miles ; Rate = 180+x mph ; Time = d/r = 7/(180+x) hrs
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\n" ); document.write( "Against the wind DATA:
\n" ); document.write( "Distance = 5 miles ; Rate = 180-x mph ; Time = d/r = 5/(180-x) hrs
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\n" ); document.write( "EQUATION:
\n" ); document.write( "time with wind = time against wind
\n" ); document.write( "7/(180+x) = 5/(180-x)
\n" ); document.write( "7*180-7x = 5*180+5x
\n" ); document.write( "12x = 2*180
\n" ); document.write( "x = 30 (wind speed)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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