Answer:
Magnitude of avg velocity, 

Given:
Constant speed of train, v = 79 km/h
Time taken in East direction, t = 27 min = 
Angle, 
Time taken in
east of due North direction, t' = 29 min = 
Time taken in west direction, t'' = 37 min = 
Solution:
Now, the displacement, 's' in east direction is given by:

Displacement in
east of due North for 29.0 min is given by:



Now, displacement in the west direction for 37 min:

Now, the overall displacement,



(a) Now, average velocity,
is given:



Magnitude of avg velocity is given by:

(b) angle can be calculated as:

