A bus covered 60 km at a speed of 15 km/h, 100 km at a speed of 25 km/h, and 20 km at a speed of 5 km/h. What is its average speed during the entire journey (in km/hr)?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 15
Given that
A bus covered 60 km at a speed of 15 km/h, 100 km at a speed of 25 km/h and 20 km at a speed of 5 km/h
Total Distance covered by the bus = 60 + 100 + 20 = 180 km
Total Time taken by bus = (60/15) + (100/25) + (20/5) = 4 + 4 + 4 =12 hours
As we know,
The average speed = Total distance covered/Total time taken
The average speed = 180/12 = 15 km/h