Question

Abdul, while driving to school, computes the average speed for his trip to be 20 km h . On his return trip along the same route, there is less traffic and the average speed is 30 km h. What is the average speed for Abduls trip?

Answer 1

Let’s say the distance while driving to school is ‘x’.
So while driving to school time taken will be (x/20) hour and while returning the time taken is (x/30) hour.
Total distance of entire journey is ‘2x’.
Total time taken is (x/20)+(x/30).
Average speed= total distance/total time.
Average speed= 2*600/50=24 km/h.

Answer 2

let the total distance is X.
time taken in route to school=X/20sec.
time taken in route to home=X/30sec.
total distance=2X
so average speed of total journey=2X/(1/6X)=12m/s