Question 360271
A salmon swims 24 km downstream from its birthplace to the ocean in three hours. The return trip upstream to spawn takes five hours. How fast does the salmon swim in its water?
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rate downstream = 24/3 = 8 km/h
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rate upstream = 24/5 = 4.8 km/h
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Equations:
s + c = 8 km/h
s - c = 4.8 km/h
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Add and solve for "s":
2s = 12.8 
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salmon's swim rate  = 6.4 km/h
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Cheers,
Stan H.
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