document.write( "Question 758580: The sanderling is a small shorebird about 6.5 in. long, with a thin, dark bill and a wide, white wing stripe. If a sanderling can fly 30 mi with the wind in the same time it can fly 18 mi against the wind when the wind speed is 8 mph, what is the speed of the bird in still air? \n" ); document.write( "
Algebra.Com's Answer #461580 by ankor@dixie-net.com(22740)\"\" \"About 
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If a sanderling can fly 30 mi with the wind in the same time it can
\n" ); document.write( " fly 18 mi against the wind when the wind speed is 8 mph,
\n" ); document.write( " what is the speed of the bird in still air?
\n" ); document.write( ":
\n" ); document.write( "Let s = bird speed in still air
\n" ); document.write( "then
\n" ); document.write( "(s+8) = ground speed of the bird with the wind
\n" ); document.write( "and
\n" ); document.write( "(s-8) = ground speed against the wind
\n" ); document.write( ":
\n" ); document.write( "Write a time equation; time = dist/speed
\n" ); document.write( ":
\n" ); document.write( "\"30%2F%28%28s%2B8%29%29\" = \"18%2F%28%28s-8%29%29\"
\n" ); document.write( "cross multiply
\n" ); document.write( "30(s-8) = 18(s+8)
\n" ); document.write( "30s - 240 = 18s + 144
\n" ); document.write( "30s - 18s = 144 + 240
\n" ); document.write( "12s = 384
\n" ); document.write( "s = 384/12
\n" ); document.write( "s = 32 mph is the speed in still air
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check this by finding the time of each way, should be equal
\n" ); document.write( "With: 30/40 = .75 hrs
\n" ); document.write( "Against: 18/24 = .75 hrs \n" ); document.write( "
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