Puneet goes to his office at the speed of 60 km/hr and returns to his home at the speed of 90 km/hr. What will be the average speed of Puneet for the whole journey?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 20 m/s
Average Speed = (2A × B)/(A + B)
Where A = Speed of person going to office
B = Speed of person returning from office
Average Speed = 2 × 60 × 90/(60 + 90)
Average Speed = 10800/150 = 360/5 km/h
To change Km/h into m/s we have to multiply the value by 5/18
⇒ 360 × 5/18 × 5 = 20m/s.