document.write( "Question 1046114: Heather's boat has a top speed of
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\n" ); document.write( " miles per hour in still water. While traveling on a river at top speed, she went
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\n" ); document.write( "30
\n" ); document.write( " miles downstream. Find the rate of the river current.
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Algebra.Com's Answer #661625 by ankor@dixie-net.com(22740)\"\" \"About 
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boat has a top speed of 6 miles per hour in still water.
\n" ); document.write( " While traveling on a river at top speed, she went 10 miles upstream in the same amount of time she went 30 miles downstream.
\n" ); document.write( " Find the rate of the river current.
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\n" ); document.write( "let c = the rate of the current
\n" ); document.write( "then
\n" ); document.write( "(6-c) = effective speed upstream
\n" ); document.write( "and
\n" ); document.write( "(6+c) = effective speed downstream
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\n" ); document.write( "Write a time equation; time = dist/speed
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\n" ); document.write( "time up = time down
\n" ); document.write( "\"10%2F%28%286-c%29%29\" = \"30%2F%28%286%2Bc%29%29\"
\n" ); document.write( "cross multiply
\n" ); document.write( "10(6+c) = 30(6-c)
\n" ); document.write( "distribute
\n" ); document.write( "60 + 10c = 180 - 30c
\n" ); document.write( "10c + 30c = 180 - 60
\n" ); document.write( "40c = 120
\n" ); document.write( "c = 120/40
\n" ); document.write( "c = 3 mph is the rate of the current
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\n" ); document.write( "Check this; find the actual time each way
\n" ); document.write( "10/(6-3) = 3.33 hrs
\n" ); document.write( "30/(6+3) = 3.33 hrs \n" ); document.write( "
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