document.write( "Question 147408: An airplane flew for 3 hours with a tail wind of 40 km/hr. The Return flight against the same wind took 4 hours. Find The Speed of the airplane in still air. \n" ); document.write( "
Algebra.Com's Answer #107842 by ankor@dixie-net.com(22740)\"\" \"About 
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An airplane flew for 3 hours with a tail wind of 40 km/hr. The Return flight against the same wind took 4 hours. Find The Speed of the airplane in still air.
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\n" ); document.write( "Let s = speed of plane in still air
\n" ); document.write( "then
\n" ); document.write( "(s+40) = ground speed with the wind
\n" ); document.write( "and
\n" ); document.write( "(x-40) = ground speed against the wind
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\n" ); document.write( "the distance both ways are assumed equal, write a distance equation:
\n" ); document.write( "Dist = time * speed
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\n" ); document.write( "4(s-40) = 3(s+40)
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\n" ); document.write( "4s - 160 = 3s + 120
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\n" ); document.write( "4s - 3s = 120 + 160
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\n" ); document.write( "s = 280 mph in still air
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\n" ); document.write( "Check solution by confirming that the distances are equal
\n" ); document.write( "4(280-40) = 960
\n" ); document.write( "3(280+40) = 960
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\n" ); document.write( "This is a way all these type problems can be done. Learn this and you got it! \n" ); document.write( "
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