A car covers 20 km in the first quarter of an hour, 25 km in the second quarter of that hour and 15 km in the third quarter. The average speed of the car (in km/h) over the entire journey is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 80.
Given that
Distance covered in first 15 minutes = 20 km
Distance traveled in next 15 minutes = 25 km
Distance traveled in next 15 minutes = 15 km
Total distance covered = 60 km
Total time taken = 45 minutes = 0.75 hrs
Average speed = total distance / total time taken
Hence, average speed = = 80
The average speed of the car over the entire journey is 80 km/h.