If you are at point A and you start moving ( in one direction) to point B, then back to point A ( in it's reverse direction ) is an example of a situation in which a body has a certain average speed but it's average velocity is zero.

Situation:
In a scenario where a car travels in a circular path at a constant speed, it is possible for the body to have an average speed but an average velocity of zero.

Explanation:
- When a car moves in a circular path at a constant speed, it covers the same distance in the same amount of time for each complete circle.
- The average speed of the car can be calculated by dividing the total distance traveled by the total time taken.
- However, the average velocity of the car is determined by the displacement vector, which is the shortest distance between the initial and final positions, divided by the total time taken.
- In the case of the car moving in a circular path, the displacement vector is zero because the car ends up at the same position as where it started.
- Therefore, even though the car has a non-zero average speed due to covering a certain distance, its average velocity is zero because there is no net displacement over the entire journey.
This situation highlights the distinction between speed and velocity, where speed is a scalar quantity that represents the rate at which an object covers distance, while velocity is a vector quantity that considers both the speed and direction of an object's motion.