The velocity of the river is 2 km/hr in the direction of the boat.
this is because resultant velocity=Velocity of boat +velocity of river
since the resultant velocity is showing an increase in the boat's velocity ;
10 km/hr=8 km/hr+velocity of river
therefore ,
velocity of river=10 km/hr-8 km/hr=2 km/hr.
hope i helped u:)

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As the velocity of boat is rising in water, it shows that the boat is travelling in the direction of river.So,
resultant speed = speed of boat + speed of river
speed of river = resultant speed - speed of boat
speed of river = (10 - 8)km/hr = 2 km/hr
Therefore, speed of river = 2 km/hr

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