A 400.0-m-wide river flows from west to east at 30.0 m/min. Your boat moves at 100.0 m/min relative to the water no matter which direction you point it. To cross this river, you start from a dock at point A on the south bank. There is a boat landing directly opposite at point B on the north bank, and also one at point C, 75.0 m downstream from B.

A) To reach point C at what bearing (angle north of west) must you aim your boat?

For this I got 83.5 deg N of W

B) Refer to part A. How long (t) will it take to cross the river?

For this I got 4.02 min

This is where I got stuck because I'm not sure how to do the last two parts...

C) Refer to part A. What distance (d, as measured by an observer on the ground) do you travel in m?

D) Refer to part A. What is the speed of your boat as measured by an observer standing on the river bank (=|VbG|) in m/min?