Question

How instataneous sspeedis same as average speed or velocity??

Answer 1

Average velocity is equal to the instantaneous velocity when acceleration is zero

Answer 2

Instantaneous speed is not the same as average speed or average velocity.

Instantaneous speed is the speed of an object at a given instant.

Average speed is total distance covered divided by total time.

Average velocity is displacement divided by total time.

All are different.

However, there's one special case when all have the same magnitude:

When a body is travelling with a constant velocity in a straight line, then all three quantities hold same values.