Question

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

Answer 1

Answer:

24 km/Hr

Explanation:

Let say  Distance Each side  = 60D  km

Avergage Speed on trip = 20 km/hr

Time taken = Distance / Average Speed

=> Time taken =  60D/20  = 3D hr

on return Trip Avergage Speed = 30 km/hr

Time Taken on Return Trip = 60D/30  = 2D hr

Total Time Taken = 3D + 2D = 5D hr

Total Distance travelled = 60D + 60D = 120D km

Average Speed of complete trip = 120D/5D  = 24 km/Hr