Amy
Regardless of the path taken, where did he end up relative to his starting point?
Include direction as well as distance.
rotchm
a) OK
b) final position - init position. here you are in 2D.
init position = (0,0)
Final position = (115,0).
final - init = (115,0) - (0,0) = (115,0).
Done.
Now, lookup the definition of 'displacement' to get a better understanding of it.