document.write( "Question 1120070: A man flies a small airplane from Fargo to Bismarck, North Dakota a distance of 180 miles. Because he is flying into a headwind, the trip takes him 2 hours. On the way back, the wind is still blowing at the same speed, so the return trip takes only 1 hour 12 minutes. What is his speed in still air, and how fast is the wind blowing?
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Algebra.Com's Answer #735730 by ankor@dixie-net.com(22740)\"\" \"About 
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A man flies a small airplane from Fargo to Bismarck, North Dakota a distance of 180 miles.
\n" ); document.write( " Because he is flying into a headwind, the trip takes him 2 hours.
\n" ); document.write( " On the way back, the wind is still blowing at the same speed, so the return trip takes only 1 hour 12 minutes.
\n" ); document.write( " Change 1 hr 12 min to 1.2 hrs
\n" ); document.write( " What is his speed in still air, and how fast is the wind blowing?
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\n" ); document.write( "let s = aircraft speed in still air
\n" ); document.write( "let w = speed of the wind
\n" ); document.write( "then
\n" ); document.write( "(s-w) = effective speed into a headwind
\n" ); document.write( "and
\n" ); document.write( "(s+w) = effective speed with the wind
\n" ); document.write( ":
\n" ); document.write( "Write dist equation for each way; (dist = time * speed
\n" ); document.write( "2(s-w) = 180
\n" ); document.write( "1.2(s+w) = 180
\n" ); document.write( ":
\n" ); document.write( "Simplify, divide the 1st equatio by 2 and the 2nd equation by 1.2
\n" ); document.write( "s - w = 90
\n" ); document.write( "s + w = 150
\n" ); document.write( "--------------addition eliminates w, find s
\n" ); document.write( "2s + 0 = 240
\n" ); document.write( "s = 240/2
\n" ); document.write( "s = 120 mph the speed in still air
\n" ); document.write( "and
\n" ); document.write( "12 + w = 150
\n" ); document.write( "w = 30 mph is the wind
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\n" ); document.write( "Check this; find the distance with these values
\n" ); document.write( "2(120-30) = 180
\n" ); document.write( "1.2(120+30) = 180\r
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