Crossing the River II (a) In which direction should the motorboat in Exercise 3.41 head in order

Question:

Crossing the River II (a) In which direction should the motorboat in Exercise 3.41 head in order to reach a point on the opposite bank directly east from the starting point? (The boat's speed relative to the water remains 4.2 m/s.)
(B) What is the velocity of the boat relative to the earth?
(c) How much time is required to cross the river?