document.write( "Question 720815: Don Williams uses his small motorboat to go 4 miles upstream to his favorite fishing spot. Against the current, the trip takes 2/5 hours. With the current the trip takes 1/5. How fast can the boat travel in still water. What is the speed of the current?? thanks. \n" ); document.write( "
Algebra.Com's Answer #441989 by stanbon(75887)\"\" \"About 
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Don Williams uses his small motorboat to go 4 miles upstream to his favorite fishing spot. Against the current, the trip takes 2/5 hours. With the current the trip takes 1/5. How fast can the boat travel in still water. What is the speed of the current??
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\n" ); document.write( "Upstream DATA:
\n" ); document.write( "distance = 4 miles ; time = 2/5 hr. ; rate = d/t = 4/(2/5) = 10 mph
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\n" ); document.write( "Downstream DATA:
\n" ); document.write( "distance = 4 miles ; time = 1/5 hr ; rate = d/t = 4/(1/5) = 20 mph
\n" ); document.write( "------------
\n" ); document.write( "Equation:
\n" ); document.write( "b + c = 20 mph
\n" ); document.write( "b - c = 10 mph
\n" ); document.write( "-----
\n" ); document.write( "2b = 30
\n" ); document.write( "b = 15 mph (speed of the boat in still water)
\n" ); document.write( "----
\n" ); document.write( "b + c = 20 mph
\n" ); document.write( "15 + c = 20
\n" ); document.write( "c = 5 mph (speed of the current)
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\n" ); document.write( "cheers,
\n" ); document.write( "Stan H.
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