Answer:
It must be moving at an angle
with East towards North
Step-by-step explanation:
As we know that boat headed towards North while river is flowing towards East
So here the resultant velocity of boat is vector sum of velocity of river and velocity of boat.
So we will find the vector resultant as

here we know
= velocity of boat towards North
= velocity of river towards East
now if we add two vectors along North and and east then the resultant must be between North and East so the boat will move at some angle
with East towards North