document.write( "Question 614000: A boat travels 120 km downstream in 4 hours and takes 6 hours to return. How long will it take in still water? \n" ); document.write( "
Algebra.Com's Answer #386479 by ankor@dixie-net.com(22740)\"\" \"About 
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A boat travels 120 km downstream in 4 hours and takes 6 hours to return.
\n" ); document.write( "How long will it take in still water?
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\n" ); document.write( "Let s = boat speed in still water
\n" ); document.write( "Let c = rate of the current
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\n" ); document.write( "Write a distance equation; dist = speed * time, for each scenario>
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\n" ); document.write( "4(s + c) = 120
\n" ); document.write( "6(s - c) = 120
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\n" ); document.write( "simplify, divide the 1st equation by 4, divide the 2nd equation by 6:
\n" ); document.write( "s + c = 30
\n" ); document.write( "s - c = 20
\n" ); document.write( "------------adding eliminates c, find s
\n" ); document.write( "2s = 50
\n" ); document.write( "s = 50/2
\n" ); document.write( "s = 25 km/h, speed in still water
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\n" ); document.write( "You can find the rate of the current and check in both equations
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