SOLUTION: 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?

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: 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?      Log On


   

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?
Found 2 solutions by mananth, stanbon:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
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?
salmon speed = x
cirrent speed =y
d/r=t
downstream
24/x+y=3
3x+3y=24
/3
x+y=8.................1
upstream
24/(x-y)=5
5x-5y=24..............2
multiply 1 by 5
5x+5y=40
add it to 2
10x=64
x= 6.4 salmon 's speed
current speed = 1.6 mph
...
m.ananth@hotmail.ca

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
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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