SOLUTION: A boat travels 14 km/h in still water.If this boat goes upstream in a river flowing at a rate of 4 km/h, for 3 km, and then returns back downstream to its starting point, what is t

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Question 1097806: A boat travels 14 km/h in still water.If this boat goes upstream in a river flowing at a rate of 4 km/h, for 3 km, and then returns back downstream to its starting point, what is the average speed for the whole trip in km/h?
Answer by jorel1380(3719) About Me  (Show Source):
You can put this solution on YOUR website!
The boat travels for 3 km at a speed of 14+4, or 18 km/h. 3/18 km=1/6 hours, or 10 minutes. Going back, it's 3 km at 14-4, or 10 km/h, for 3/10 hours, or 18 mins. So:
6 x 60/28=12.857142857 km/h as the average speed for the trip
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