document.write( "Question 618025: A tugboat goes 120 miles upstream in 20 hrs. the return trip downstream takes 5 hrs. find the speed of the tugboat without a current and the speed of the current
\n" ); document.write( "The speed of the tugboat is
\n" ); document.write( "The speed of the current is
\n" ); document.write( "simplify your answers \n" ); document.write( "
Algebra.Com's Answer #388760 by ankor@dixie-net.com(22740)\"\" \"About 
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): A tugboat goes 120 miles upstream in 20 hrs.
\n" ); document.write( " the return trip downstream takes 5 hrs.
\n" ); document.write( " find the speed of the tugboat without a current and the speed of the current
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\n" ); document.write( "Let s = boat speed in still water
\n" ); document.write( "Let c = speed of the current
\n" ); document.write( "then
\n" ); document.write( "(s-c) = effective speed upstream
\n" ); document.write( "and
\n" ); document.write( "(s+c) = effective speed downstream
\n" ); document.write( ":
\n" ); document.write( "Write distance equation for each way. (dist = time * speed
\n" ); document.write( "20(s-c) = 120
\n" ); document.write( "5(s+c) = 120
\n" ); document.write( "Simplify both equations, divide the 1st equation by 20, divide the 2nd equation by 5, results:
\n" ); document.write( "s - c = 6
\n" ); document.write( "s + c = 24
\n" ); document.write( "-----------Adding eliminates c find s
\n" ); document.write( "2s = 30
\n" ); document.write( "s = 30/2
\n" ); document.write( "s = 15 mph boat speed in still water
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\n" ); document.write( "You can find the current, check the solutions in the original equations\r
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