document.write( "Question 143308This question is from textbook
\n" ); document.write( ": The Hudson River flows at a rate of 3mph. a Patrol boat travels 60mi upriver and returns in a total time of 9 hr. What is the speed of the boat in still water? \n" ); document.write( "
Algebra.Com's Answer #104315 by stanbon(75887)\"\" \"About 
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The Hudson River flows at a rate of 3mph. a Patrol boat travels 60 mi upriver and returns in a total time of 9 hr. What is the speed of the boat in still water?
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\n" ); document.write( "Let \"b\" be the speed of the boat in still water.
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\n" ); document.write( "Upriver DATA:
\n" ); document.write( "distance = 60 mi ; rate = b-3; time = d/r = 60/(b-3) hrs.
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\n" ); document.write( "Downriver DATA:
\n" ); document.write( "distance = 60 mi ; rate = b+3 ; time = 60/(b+3) hrs.
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\n" ); document.write( "EQUATION:
\n" ); document.write( "time + time = 9 hrs.
\n" ); document.write( "60/(b-3) + 60/(b+3) = 9
\n" ); document.write( "60b+180 + 60b-180 = 9(b^2-9)
\n" ); document.write( "120b = 9b^2-81
\n" ); document.write( "3b^2 - 40b - 27 = 0
\n" ); document.write( "Using a calculator I get b = 13.97 mph\r
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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