SOLUTION: Marie and Marco are paddling a canoe together. In still water, the pair moves at a speed of 7km/h. Taking a trip along the river, it takes the pair 2 hours to go 3km up a river and

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Question 1074979: Marie and Marco are paddling a canoe together. In still water, the pair moves at a speed of 7km/h. Taking a trip along the river, it takes the pair 2 hours to go 3km up a river and 3km back down. What is the speed of the current in the river? Round to the nearest tenth of a km/h.

Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
               SPEED        TIME       DISTANCE

UP             7-c          3/(7-c)     3    

DOWN           7+c          3/(7+c)     3

Total                         2

Sum of the times
3%2F%287-c%29%2B3%2F%287%2Bc%29=2

Solve for c.



c=2sqrt%287%29