Problem 3-9 - Vector sum

Find the magnitude and direction of the sum of the vectors \(A + B + C\) using the component technique. Assume two significant digits.
\(A = 20\; km\) north, \(B = 30\; km\) east, \(C = 50\; km\; 55 ^\circ\) west of north.

We have 3 vectors referred to the directions \(\text{N, S, E, W}\) and we must choose a set of coordinate axes. Of course any \(x, y\) set will do but which of the selections below would provide the simplest solution?

direction vector 1

direction vector 2

direction vector 3

direction vector 4