Answer
The direction of motion is toward the west.
Work Step by Step
$r = (3500 - 160t)~\hat{i} + 2700~\hat{j} + 300~\hat{k}$
$v = \frac{dr}{dt} = (-160~\hat{i})~m/s$
It is given in the question that the x axis points east.
Since the velocity is negative, the direction of motion is toward the west.
