document.write( "Question 121239: Traveling against the current, the Scouts paddled 20km in 4 h. The return trip with the current took 1.5 h less. Find (a) the Scout's paddling rate in still water and (b) the rate of the current. \n" ); document.write( "
Algebra.Com's Answer #89009 by ankor@dixie-net.com(22740)\"\" \"About 
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Traveling against the current, the Scouts paddled 20 km in 4 h. The return trip with the current took 1.5 h less. Find (a) the Scout's paddling rate in still water and (b) the rate of the current.
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\n" ); document.write( "Let x = paddling rate in still water
\n" ); document.write( "Let y = rate of the current:
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\n" ); document.write( "Time upstream given as 4 hr
\n" ); document.write( "Time downstream: 4 - 1.5 = 2.5 hrs
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\n" ); document.write( "Write two distance equations:
\n" ); document.write( "one for upstream and one for downstream (Dist = time * speed
\n" ); document.write( "4(x-y) = 20
\n" ); document.write( "2.5(x+y) = 20
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\n" ); document.write( "Simplify both equations: divide the 1st eq by 4 and the 2nd eq by 2.5
\n" ); document.write( "x - y = 5
\n" ); document.write( "x + y = 8
\n" ); document.write( "------------adding eliminates y, find x
\n" ); document.write( "2x + 0 = 13
\n" ); document.write( "x = 13/2
\n" ); document.write( "x = 6.5 km/h speed in still water
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\n" ); document.write( "Find y using x + y = 8
\n" ); document.write( "6.5 + y = 8
\n" ); document.write( "y = 8 - 6.5
\n" ); document.write( "y = 1.5 km/hr is the current
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\n" ); document.write( "Check solution by finding if the distances are equal
\n" ); document.write( "4(6.5 - 1.5) = 20
\n" ); document.write( "and
\n" ); document.write( "2.5(6.5 + 1.5) = 20
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\n" ); document.write( "Could you follow this OK?
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