document.write( "Question 582554: It takes Sally three minutes to go one mile with the wind at her back. Then it takes her four minutes on the ride back with the wind against her. What is the rate of the speed of the wind? Please help me. I tried this and got the answer of one over twentyfour. \n" ); document.write( "

Algebra.Com's Answer #372230 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

You can put this solution on YOUR website!
It takes Sally three minutes to go one mile with the wind at her back.
\n" ); document.write( " Then it takes her four minutes on the ride back with the wind against her.
\n" ); document.write( " What is the rate of the speed of the wind?
\n" ); document.write( ":
\n" ); document.write( "Assume they want the speeds in mph
\n" ); document.write( ":
\n" ); document.write( "Convert 1 mi in 3 min to mph
\n" ); document.write( " $\"1%2F%283%2F60%29\"$ = 20 mph effective speed with the wind
\n" ); document.write( "and
\n" ); document.write( " $\"1%2F%284%2F60%29\"$ = 15 mph effective speed against the wind
\n" ); document.write( ":
\n" ); document.write( "Let s = speed in still air
\n" ); document.write( "Let w = speed of the wind
\n" ); document.write( ":
\n" ); document.write( "s + w = 20
\n" ); document.write( "s - w = 15
\n" ); document.write( "-----------adding eliminates w, find s
\n" ); document.write( "2s = 35
\n" ); document.write( "s = 35/2
\n" ); document.write( "s = 17.5 mph in still air
\n" ); document.write( ":
\n" ); document.write( "Find the speed of the wind
\n" ); document.write( "17.5 + w = 20
\n" ); document.write( "w = 20 - 17.5
\n" ); document.write( "w = 2.5 mph is the rate of the wind
\n" ); document.write( " \n" ); document.write( "

\n" );