Relative velocity questions are bugging me as well
However, to solve them , you need to break them down logically...
Relative velocity literally means velocity relative to another....
If they give you an airplane and wind question, you will basically need to know that
V(plane) = V(plane in still air) + V(wind)
This statement holds true if you think it through logically...
In still air, there is no wind, thereforoe your plane will have a certain velocity
However when the wind vector has been added, you need add that to your velocity in still air to calculate your overall velocity of the plane