A car travels a distance of 120 km at a speed of 20 km/hr and returns the same distance at a speed of 30 km/hr. What is the average speed of the car for the entire journey?
Show answer & explanation
Correct answer: B
Explanation
Given:
Outward distance = 120 km, speed = 20 km/h
Return distance = 120 km, speed = 30 km/h
Time taken for the outward journey = 120/20 = 6 hours
Time taken for the return journey = 120/30 = 4 hours
Total distance = 120 + 120 = 240 km
Total time = 6 + 4 = 10 hours
Average speed = Total distance / Total time
= 240/10
= 24 km/h