You should have the definition of velocity as the displacement of an object over a given time. Often, it is also defined as the speed of an object in a given direction. Displacement is defined as the change in the position of an object, and it must include the direction of that displacement.
Just imagine if you were on a sports field with the ball, and you ran as fast as you could toward the goal at the end. The direction that you ran would mean the difference between running toward the right goal or the wrong goal! Even though you can run at the same rate, a different direction gives a different result. Likewise, driving a car eastward on a highway will get you either closer to your destination, or farther away.
As this problem indicates the displacement of the car (how far it travels and in what direction) as well as the time it took, use the formula to calculate the velocity. Just make sure to include the direction.
