document.write( "Question 129744: Fat Chance can row his boat 9 miles up Moss Creek in the same time that it takes him to row 15 miles down the creek. If fat can row 2 miles per hour in still water, how fast is the current in Moss Creek? \n" ); document.write( "

Algebra.Com's Answer #94737 by ptaylor(2198) $\"\"$ $\"About$

You can put this solution on YOUR website!
Distance(d) equals Rate(r) times Time(t) or d=rt; r=d/t and t=d/r\r
\n" ); document.write( "\n" ); document.write( "Let r=rate (speed) of the current in Moss Creek\r
\n" ); document.write( "\n" ); document.write( "Fat's rate upstream is (2-r) and his rate downstream is (2+r)\r
\n" ); document.write( "\n" ); document.write( "Fat's time upstream is (d/r)=9/(2-r)
\n" ); document.write( "Fat's time downstream is (d/r)=15/(2+r)\r
\n" ); document.write( "\n" ); document.write( "Now we are told that the above times are equal, so:\r
\n" ); document.write( "\n" ); document.write( "9/(2-r)=15/(2+r) multiply each side by (2-r)(2+r) or cross-multiply\r
\n" ); document.write( "\n" ); document.write( "9(2+r)=15(2-r) get rid of parens\r
\n" ); document.write( "\n" ); document.write( "18+9r=30-15r subtract 9r and also 30 from each side\r
\n" ); document.write( "\n" ); document.write( "18-30+9r-9r=-15r-9r+30-30 collect like terms\r
\n" ); document.write( "\n" ); document.write( "-12=-24r divide both sides by -24\r
\n" ); document.write( "\n" ); document.write( "r=0.5 mph-----------------------------rate of current\r
\n" ); document.write( "\n" ); document.write( "CK\r
\n" ); document.write( "\n" ); document.write( "9/1.5=15/2.5\r
\n" ); document.write( "\n" ); document.write( "6=6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor \n" ); document.write( "

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