Step-by-step explanation:
Given that,
Velocity of boat,

Velocity of current,

(a) If the boat is traveling to the north and the current is to the south,


The resultant velocity,
due North
(b) If boat is traveling to the south and the current is to the south,


Resultant velocity,
due south
(c) If the boat travels to the east, across the current, while the current is to the south.
So,
