Afisherman traveled in a boat from point n upstream. after having traveled 6 km, he stopped rowing and 2 hour 40 min after first leaving n, he was brought back to n by the current. knowing that the speed of the boat in still water is 9 km/hour, find the speed of the river’s current.

The speed of the river's current is 4.5 km/hr.

Step-by-step explanation:

Given : A fisherman traveled in a boat from point N upstream.

After having traveled 6 km, he stopped rowing and 2 hour 40 min after first leaving N, he was brought back to N by the current.

Knowing that the speed of the boat in still water is 9 km/hour

To find : The speed of the river’s current.

Solution :

Let the speed of current  = x km/h

Speed of boat = 9 km/h

Thus, the speed in upstream = (9 - x) km/h

Also, the speed in downstream = x km/h (because the boat is stationary in downstream)

Total distance = 6 km ( from N to the point he reached )

Total time = 2 hours 40 minutes

We know,

According to the question,

Taking LCM and 6 common

Take 6 to another side,

Cross multiply,

Taking 4 common and cancel out

Solve quadratic equation by middle term split,

Therefore, The speed of the river's current is 4.5 km/hr.

something over 10 so ? /10

step-by-step explanation: