A train covers half of his journey at 60 km/h and the remaining half at 40 km/h. It's average speed is-

Question: A train covers half of his journey at 60 km/h and the remaining half at 40 km/h. It's average speed is-

Solution:
let,
The total distance is 2x
First x distance is covered in 60 km/h
∴ time = x/60 h

Second x distance is covered in 40 km/h
∴ time = x/40 h

∴ Average Speed = Total distance ÷ Total time
= 2x ÷ {(x/60) + (x/40)}
= 2x ÷ (5x/120)
= 2x ÷ (x/24)
= 48