document.write( "Question 662501: Jeremiah can kayak downstream a distance of 21 kilometers in 3 hours. Going upstream, he can kayak a distance of only 24 kilometers in 4 hours. How fast could Jeremiah kayak in still water (if there were no current)? \n" ); document.write( "
Algebra.Com's Answer #412298 by stanbon(75887)\"\" \"About 
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Jeremiah can kayak downstream a distance of 21 kilometers in 3 hours. Going upstream, he can kayak a distance of only 24 kilometers in 4 hours. How fast could Jeremiah kayak in still water (if there were no current)?
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\n" ); document.write( "Downstream rate: dist/time = 21/3 = 8 km/hr
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\n" ); document.write( "Upstream rate: dist/time = 24/4 = 6 km/hr
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\n" ); document.write( "Equations
\n" ); document.write( "downstream Eq: b + c = 8 km/hr
\n" ); document.write( "upstream Eq::: b - c = 6 km/hr
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\n" ); document.write( "Add and solve for \"b\":
\n" ); document.write( "2b = 14 km/hr
\n" ); document.write( "boat speed = 7 km/hr
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\n" ); document.write( "Solve for \"c\":
\n" ); document.write( "b + c = 8
\n" ); document.write( "7 + c = 8
\n" ); document.write( "current = 1 km/hr
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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