A person goes from A to B with a speed of 30 km/h. He comes back from B to A with a speed of 20 km/h. What is his average speed for the entire journey?
Answer & explanation
Correct answer: option 4
Average speed = 2xy/(x + y)
Here, x = speed from A to B
y = speed from B to A
⇒ Average = 2 × 30 × 20/(30 + 20)
⇒ Average = 24 km/h