document.write( "Question 195283This question is from textbook
\n" ); document.write( ": A small plane travels 520 miles with the wind in 3 hours, 20 mins (3 1/3 hours), the same time that it takes to travel 460 miles against the wind. what is the plane's speed in still air? \n" ); document.write( "
Algebra.Com's Answer #146493 by ptaylor(2198)\"\" \"About 
You can put this solution on YOUR website!
Distance(d) equals Rate(r) times Time(t) or d=rt; r=d/t and t=d/r
\n" ); document.write( "Let r=speed of plane in still air
\n" ); document.write( "And let w=windspeed
\n" ); document.write( "(With the wind, we add windspeed, against, we subtract)
\n" ); document.write( "r+w=520/(3 1/3)=520/(10/3)=1560/10=156 mph-----eq1
\n" ); document.write( "r-w=460/(3 1/3)=460/(10/3)=1380/10=138 mph---eq2
\n" ); document.write( " add eq1 and eq2\r
\n" ); document.write( "\n" ); document.write( "2r=294
\n" ); document.write( "r=147 mph-------------speed of plane in still air
\n" ); document.write( "substitute into eq1
\n" ); document.write( "147+w=156
\n" ); document.write( "w=156-147=9 mph ------speed of wind
\n" ); document.write( "CK
\n" ); document.write( "520/156=3 1/3 hr
\n" ); document.write( "460/138=3 1/3 hr\r
\n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor
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