A man goes uphill with an average speed of 24 km/h and comes down with an average speed of 36 km/h. The distance travelled in both cases being the same. The average speed for the entire journey is:
Answer & explanation
Correct answer: option 2
Average of speed during uphill (S1) = 24 kmph
Average of speed during down (S2) = 36 kmph
Average speed = (2 × S1 × S2)/(S1 + S2)
Average speed = (2 × 24 × 36)/(24 + 36)
⇒ 1728/60 = 28.8 kmph