document.write( "Question 435236: Sara decides to canoe 3 miles upstream on a river to a waterfall and then come back. Total trip is 6 hours. Sara can canoe at the average speed of 3mph in still water. What is the speed of the current? \n" ); document.write( "
Algebra.Com's Answer #301277 by stanbon(75887)\"\" \"About 
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Sara decides to canoe 3 miles upstream on a river to a waterfall and then come back. Total trip is 6 hours. Sara can canoe at the average speed of 3mph in still water. What is the speed of the current?
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\n" ); document.write( "Upstream DATA:
\n" ); document.write( "distance = 3 miles ; rate = 3-c mph ; time = d/r = 3/(3-c) hrs
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\n" ); document.write( "Downstream DATA:
\n" ); document.write( "distance = 3 miles; rate = 3+c mph ; time = d/r = 3/(3+c) hrs
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\n" ); document.write( "Equation:
\n" ); document.write( "time + time = 6 hrs.
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\n" ); document.write( "3/(3-c) + 3/(3+c) = 6
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\n" ); document.write( "1/(3-c) + 1/(3+c) = 2
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\n" ); document.write( "(3+c) + (3-c) = 2(9-c^2)
\n" ); document.write( "6 = 2(9-c^2)
\n" ); document.write( "3 = 9-c^2
\n" ); document.write( "c^2 = 6
\n" ); document.write( "c = sqrt(6) (speed of the current)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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