SOLUTION: A sailboat travels 20 miles downstream in 3 hours. It returns in 4 hours. Find the speed of the sailboat in still water and the rate of the current. (using the 5- step method )

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Question 91212: A sailboat travels 20 miles downstream in 3 hours. It returns in 4 hours. Find the speed of the sailboat in still water and the rate of the current. (using the 5- step method )
Found 2 solutions by stanbon, checkley71:
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
A sailboat travels 20 miles downstream in 3 hours. It returns in 4 hours. Find the speed of the sailboat in still water and the rate of the current.
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Draw the picture:
Symbolize the DATA:
Downstream DATA:
distance= 20 miles; time = 3 hrs ; rate = 20/3 hrs
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Upstream DATA:
distance = 20 miles; time = 4 hrs ; rate = 20/4 = 5 hrs
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Let speed in still water be "b"
Let speed of the current be "c"
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EQUATION:
b+c=20/3
b-c=5
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Add the two equations:
2b = 35/3
b = 35/6 mph (speed of the boat in still water)
Solve for c:
35/6 + c = 40/6
c=5/6 mph (speed of the current)
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Cheers,
Stan H.

Answer by checkley71(8403) (Show Source):
You can put this solution on YOUR website!
20/3=S+C S=SPEED & C=CURRENT
20/4=S-C NOW ADD THESE TWO EQUATIONS
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20/3+20/4=2S
(20*4+20*3)/12=2S
(80+60)/12=2S
140/12=2S
2S=140/12
2S=11.6667
S=11.6667/2
S=5.833 ANSWER FOR THE SPED OF THE SAIL BOAT.
20/4=5.8333-C
5=5.8333-C
C=5.8333-5
C=.8333 SPEED OF THE CURRENT.
PROOF
20/3=5.8333+.8333
6.6667=6.6667