Question 117200: a cruise boat travels 24 miles downstream in 3 hours and returns to its starting point upstream in 6 hours. find the speed of the stream. Found 2 solutions by stanbon, checkley71:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! a cruise boat travels 24 miles downstream in 3 hours and returns to its starting point upstream in 6 hours. find the speed of the stream.
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Downstream DATA:
distance = 24 miles ; time = 3 hrs ; rate = 24/3 = 8 mph
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Upstream DATA:
distance = 24 miles ; time = 6 hrs ; rate = 4 mph
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Let b = boat speed; let c = current speed.
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EQUATIONS:
b+c = 8 mph
b-c = 4 mph
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Add the two equations to solve for "b":
2b = 12
b = 6 mph ( boat speed in still water )
Substitute to solve for "c":
6 + c = 8
c = 2 mph (current speed)
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Cheers,
Stan H.
You can put this solution on YOUR website! 24/3=8 MPH FOR THE TRIP DOWNSTREAM.
24/6=4 MPH FOR THE RETURN TRIP.
NOW YOU HAVE 2 EQUATIONS.
R+S=8 WHERE WHERE R=THE RATE OF THE CRUISE BOAT & S=THE STREAM SPEED.
R-S=4 NOW ADD THESE TO FIND THE.
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2R=12
R=12/2
R=6 MPH RATE OF THE CRUISE BOAT.
THEREFORE
6+S=8
S=8-6
S=2 MPH FOR THE SPEED OF THE STREAM.
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