A man wishes to row the shortest possible distance from north to south across a river which is flowing at 3 km/hr from the east. He can row at 5 km/hr.

(a) In which direction should he steer?
At an angle (in degrees) of ? west east of south.

(b) Suppose that when the man is in the middle of the river, a wind of 6 km/hr from the southwest starts.

In which direction should he steer to move straight across the river?
At an angle (in degrees) of ? west east of south.

Which bank of the river will the rower reach first?
? The north The south Neither bank.