A delivery car handles a total route profile of 360 km. It clears the first half stretch at 45 km/h and the second half at 90 km/h. Find the net average speed. MCQ with Answer and Explanation

Explanation:
Upstream speed = 10 - 2 = 8 km/h. Time taken = 24 / 8 = 3 hours.

Explanation:
Time = Distance / Speed = 1800 / 600 = 3 hours.

Explanation:
Speed of train = 54 km/h = 15 m/s. Speed of man = 6 km/h = 5/3 m/s. Relative speed = 15 - 5/3 = 40/3 m/s. Length of train = Relative speed * time = (40/3) * 12 = 160 meters. To pass bridge: Total distance = Length of train + Length of bridge = 15 m/s * 20 seconds = 300 meters. Length of bridge = 300 - 160 = 140 meters.