<PRE><B>Question 433314</B>
 Nancy traveled 6 miles upstream to do some fly fishing. It took her 20 minutes longer to get there than to return. If the current in the river is 2 miles per hour, then how fast will her boat go in still water.
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Upstream DATA:
distance = 6 miles ; rate = b-2 mph; time = 6/(b-2) hrs 
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Downstream DATA:
distance = 6 miles;  rate = b+2 mph; time = 6/(b+2) mph
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Equation:
time up - time down = 1/3 hr
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6/(b-2) - 6/(b+2) = 1/3
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Multiply thru by 3(b^2-9) to get:
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18(b+2)-18(b-2) = b^2-9
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72 = b^2-9
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b^2= 81
b = 9 mph (speed of the boat in still water)
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Cheers,
Stan H. </PRE>