Question 813371: The speed of a stream is 3 km/h. A boat travels 6 km upstream in the same time it takes to travel 10 km downstream. What is the speed of the boat in still water?
Answer by TimothyLamb(4379)   (Show Source):
You can put this solution on YOUR website! w = 3 kph
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s = d / t
t = d / s
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6/(b - w) = 10/(b + w)
10/(b + w) - 6/(b - w) = 0
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10(b - w)/((b + w)(b - w)) - 6(b + w)/((b + w)(b - w)) = 0
10(b - w) - 6(b + w) = 0 * ((b + w)(b - w))
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10(b - 3) - 6(b + 3) = 0
10b - 30 - 6b - 18 = 0
4b - 48 = 0
4b = 48
b = 12
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Answer:
the speed of the boat in still water is 12 kph
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