Answer:
35 km/h
Explanation:
Since both the boat and river travel in the same direction, the resultant vector is found by adding the speed of the water current and that of the boat hence 10 km/h+ 25 km/h= 35 km/h and the direction is towards the South as given for the river current. In case the river current and the boat were moving in counter-directions, we would have subtracted the two velocities.
