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 2
Average speed = \(\frac{2 × S1 × S2}{S1 + S2}\)
= \(\frac{2 × 30 × 20}{30 + 20}\)
= \(\frac{120}{50}\)
= 24 km/h