Answer:
Average speed = 26.67 km/h
Step-by-step explanation:
It is given that,
The first half of the journey by a body is traveled with a speed of 40 km/h and the next half is covered with a speed of 20 km/h
We need to find the average speed of the whole journey. When two speeds are given, the average speed is given by :
![v=(2v_1v_2)/(v_1+v_2)\\\\v=(2* 40* 20)/(40+20)\\\\v=26.67\ km/h](https://img.qammunity.org/2021/formulas/physics/high-school/3ledg8g3upkv6sc210szj1gdsg796c4sa5.png)
So, the average speed of the body of the whole journey is 26.67 km/h.