Shankar covers a certain distance by a car driving at 40 km/h and he returns to the starting point riding on a scooter with a speed of 20 km/h. Find the average speed of the whole journey.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. km/h.
Given that, speed of Shankar with car, S1 = 40 km/h
Speed of Shankar with scooter, S2 = 20 km/h
Average speed = 2S1S2/(S1 + S2)
According to the given question,
Average speed of Shankar = 2 × 20 × 40/(20 + 40)
⇒ 80/3 = km/h