Question 469754
it took a crew 4 hrs and 48 min to row 10.8 km upstream and back again. 
if the rate of flow of the stream was 3km/hr , what was the rowing rate of the crew in still water ?
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Roundtrip DATA:
time = 4 4/5 hrs ; distance = 10.8 km ; rate = 10.8/(24/5)= 2.25 mph
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Equation: 
Upstream rate = s-3
Downstream rate = s+3
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Average rate:
(s + 3 + s-3)/2 = 2.25
2s/2 = 2.25
s = 2.25 mph rate in still water
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Cheers,
Stan H.
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