SOLUTION: Hi would you please help me solve my homework problem. A paddle boat can move at a speed of 20km/h in still water. The boat is paddled 18km downstream in a river in the same ti

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Question 921393: Hi would you please help me solve my homework problem.
A paddle boat can move at a speed of 20km/h in still water. The boat is paddled 18km downstream in a river in the same time it takes to go 9km upstream. What is the speed of the river?
According to my teacher the anser is 20/3 km/h. Would you please show me the steps on how to solve this problem. Thank you.
Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website!
A paddle boat can move at a speed of 20km/h in still water. The boat is paddled 18km downstream in a river in the same time it takes to go 9km upstream. What is the speed of the river?
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let c=speed of the river current
20+c=speed of paddle boat downstream
20-c=speed of paddle boat upstream
travel time=distance/speed
..

18(20-c)=9(20+c)
360-18c=180+9c
27c=180
c=6 2/3=20/3
speed of the river current=20/3 km/hr