document.write( "Question 890508: A boat on a river travels downstream (with the current) between two points 20 miles apart, in one hour. The return trip (against the current) takes 2& 1/2 hours. What is the boat's speed, and what is the speed of the current? \n" ); document.write( "
Algebra.Com's Answer #539083 by lwsshak3(11628)\"\" \"About 
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A boat on a river travels downstream (with the current) between two points 20 miles apart, in one hour. The return trip (against the current) takes 2& 1/2 hours. What is the boat's speed, and what is the speed of the current?
\n" ); document.write( "***
\n" ); document.write( "let x=boat's speed (in still water)
\n" ); document.write( "let c=speed of current
\n" ); document.write( "(x+c)boat's speed (downstream)
\n" ); document.write( "(x+c)boat's speed (against current)
\n" ); document.write( "distance/speed=travel time
\n" ); document.write( "..
\n" ); document.write( "20/(x+c)=1
\n" ); document.write( "20/x-c=2.5
\n" ); document.write( "..
\n" ); document.write( "x+c=20
\n" ); document.write( "2.5x-2.5c=20
\n" ); document.write( "..
\n" ); document.write( "2.5x+2.5c=50
\n" ); document.write( "2.5x-2.5c=20
\n" ); document.write( "add
\n" ); document.write( "5x=70
\n" ); document.write( "x=14
\n" ); document.write( "c=20-x=6
\n" ); document.write( "boat's speed (in still water)=14 mph
\n" ); document.write( "let c=speed of current=6 mph
\n" ); document.write( " \n" ); document.write( "
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