An aeroplane flew from point X to Y on a bearing of 120 degree 300km apart, it then flew 450km to point Z on bearing of 60 degree

a) How far north of Y is Z.
b) How far west of Y is point X.
c) What is the bearing of Z from X.

Draw the diagram

If X is at (0,0) then
Y = (120cos30°,-120sin30°)
Z = Y + (450sin60°,450cos60°)
Now (a) can be found via Z-Y
(b) use X-Y
(c) use Z-X and convert back to angle