The average speed of the train is 100 km/hr
Explanation:
Speed refers to the rate of change in distance.
It is calculated by dividing distance by time taken.
Average speed is calculated by dividing the total distance covered and the total time taken.
In this case;
Total distance covered by the train = 80 km + 200 Km + 420 km
= 700 km
Total time taken = 1 hr + 2 hrs + 4 hrs
= 7 hrs
Therefore;
Average speed = 700 km ÷ 7 hrs
= 100 km/hr
Thus, the average speed of the train is 100 km/hr
