Akash travels the distance from his home to school in three equal parts on his bicycle at a speed of 5 km/h, 10 km/h and 15 km/h, respectively. What is the average speed of Akash going from his home to school?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 8 km/hr.
If Akash travels the distance in three equal portions. Thus let us assume that he traveled D km at speeds of 5km/h, 10 km/h, and 15 km/h.
Thus the time taken in each section would be = D/5, D/10, and D/15.
(as time taken = distance/speed)
Thus, we know that average speed = Total Distance/Total Time Taken
Thus,
Average Speed = (D + D + D)/(D/5 + D/10 + D/15)
= 90/11 = 8km/hr.