document.write( "Question 640951: Pratap Puri rowed 18 miles down the Delaware River in 2 hours, but the return trip took him 4 1/2 hours. Find the rate Pratap can row in still water, and find the rate of the current. let x = rate Pratap can row in still water and y = rate of the current. \n" ); document.write( "
Algebra.Com's Answer #403493 by lwsshak3(11628)\"\" \"About 
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Pratap Puri rowed 18 miles down the Delaware River in 2 hours, but the return trip took him 4 1/2 hours. Find the rate Pratap can row in still water, and find the rate of the current. let x = rate Pratap can row in still water and y = rate of the current.
\n" ); document.write( "**
\n" ); document.write( "x+y=speed downriver
\n" ); document.write( "x-y=speed return trip
\n" ); document.write( "travel time=distance/speed
\n" ); document.write( "..
\n" ); document.write( "18/(x+y)=2
\n" ); document.write( "18/(x-y)=4.5
\n" ); document.write( "..
\n" ); document.write( "2x+2y=18
\n" ); document.write( "4.5x-4.5y=18
\n" ); document.write( "..
\n" ); document.write( "multiply 1st equation by 2.25
\n" ); document.write( "4.5x+4.5y=40.5
\n" ); document.write( "4.5x-4.5y=18
\n" ); document.write( "add
\n" ); document.write( "9x=58.5
\n" ); document.write( "x=58.5/9=6.5
\n" ); document.write( "y=(18-2x)/2=2.5
\n" ); document.write( "rate Pratap can row in still water=6.5 mph
\n" ); document.write( "rate of the current=2.5 mph \n" ); document.write( "
\n" );