Question

While driving to college,vedant's average speed for hs trip is 20km/h.on his return trip along the same route,there is less traffic and the average speed is 40km/h.what is the average speed for vedant's trip?

Answer 1

Answer

Case I: While driving to school

Average speed of Vedant’s trip = 20 km/h

Total distance = d

Let total time taken = t1

Speed = Distance / time

20 = d / t1

t1 = d / 20…(i)

Case II: While returning from school

Total distance = d

Speed = 30 km/h

Now,total time taken = t2

Speed = distance / time

30 = d / t2

t2 = d / 30 ..... (ii)

Total distance covered in the trip = d + d = 2d

Total time taken, t = Time taken to go to school + Time taken to return to school

= t1 + t2

Total time taken = d / 20 + d / 30

= 3d + 2d / 60

= 5d / 60

= d / 12

From equations (i) and (ii),

Average Speed = 120/5

= 24 km/h

Hence, the average speed for Abdul’s trip is 24 km/h.