document.write( "Question 58639This question is from textbook
\n" ); document.write( ": Rita rows 12 km upstream and 12 km downstream in 3 hours. The speed of her boat in still water is 9 km/hr. Find the speed of the stream.\r
\n" ); document.write( "\n" ); document.write( "I am thinking that I need to use the formula Time = distance/rate? \n" ); document.write( "
Algebra.Com's Answer #40176 by stanbon(75887)\"\" \"About 
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Rita rows 12 km upstream and 12 km downstream in 3 hours. The speed of her boat in still water is 9 km/hr. Find the speed of the stream.
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\n" ); document.write( "Let the speed of the current be \"c\".
\n" ); document.write( "Upstream DATA:
\n" ); document.write( "distance= 12 km ; rate= 9-c ; time=d/r=12/(9-c)
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\n" ); document.write( "Downstream DATA:
\n" ); document.write( "distance = 12 km; rate = 9+c time=d/r = 12/(9+c)
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\n" ); document.write( "EQUATION:
\n" ); document.write( "time+time=3 hours
\n" ); document.write( "12/(9-c)+12/(9+c)= 3
\n" ); document.write( "12(9+c) +12(9-c) = 3(81-c^2)
\n" ); document.write( "108+108=243-3c^2
\n" ); document.write( "3c^2=27
\n" ); document.write( "c^2=9
\n" ); document.write( "c=3 km/hr (speed of the current)
\n" ); document.write( "cheers,
\n" ); document.write( "Stan H.
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