A person covers 55% of a distance with a speed of 40 km/hr and the remaining with a speed of 60 km/hr. What is the Distance travelled by him covered with average speed in 17 hours in km ?

For average speed when distance fractions are known: If 55% of distance is at 40 km/h and 45% at 60 km/h, the average speed is not the simple average. We use weighted harmonic mean: Avg = 1 / (0.55/40 + 0.45/60) = 1 / (0.01375 + 0.0075) = 1 / 0.02125 ≈ 47.06 km/h. Distance = Avg × Time = 47.06 × 17 ≈ 800 km. The answer rounds to 800 km.