Motion of a boy from his home to shop (in one direction) and back to home (in its reverse direction) is an example of a situation in which a body has a certain average speed but its average velocity is zero..

Example of a situation:
In a scenario where a person goes for a jog in a circular track and completes one full lap, the person's average speed can be calculated by dividing the total distance covered by the total time taken. Let's say the person completes one lap in 10 minutes, covering a distance of 1 kilometer. Therefore, the average speed would be 1 km/10 min = 0.1 km/min.

Explanation:
- Average speed: Average speed is calculated by dividing the total distance traveled by the total time taken. In this case, the person's average speed is 0.1 km/min as calculated above.
- Average velocity: Velocity is a vector quantity that includes both speed and direction. Average velocity is calculated by dividing the total displacement by the total time taken. Since the person completes one full lap and returns to the starting point, the total displacement is zero. Therefore, the average velocity is zero, even though the average speed is 0.1 km/min.
In this situation, the person's average speed is 0.1 km/min, indicating the rate at which the person covers distance. However, the average velocity is zero, signifying that there is no overall displacement in a circular motion where the starting and ending points are the same. This example illustrates how a body can have a certain average speed but its average velocity is zero in specific scenarios like circular motion.