Question

In calm water, the motorboat of Jana is moving at the speed of 16.5km/h. On a river, because of the current, the boat moves faster down the river only by raising it. Jana went up the river in 5 hours and the decent in only 2 hours. What is the speed of the current?

Answer 1

Answer: 707 km/h

Step-by-step explanation:

let c = speed of current

16.5 + c = speed of sailboat downstream

16.5 - c = speed of sailboat upstream

distance = travel time * speed

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2(16.5 + c) = 5(16.5 - c)

33 + 2c = 82.5 - 5c

7c = 49.5

c = 7.07 km/h