Both speed and velocity measures the distance traveled per unit time.
The difference between speed and velocity is that, speed is a scalar quantity which only has a magnitude and does not have a direction.
Velocity is a vector quantity and hence has both magnitude and direction.
In the 1st and 2nd case no direction is specified. So the answer is speed in these two cases.
In the 3rd and 4th case both magnitude and direction have been mentioned. Hence the answer is velocity in these two cases.
