A train passes a static observer in 8 seconds and a platform 120 meters long in 14 seconds. Find the length of the train. MCQ with Answer and Explanation

Explanation:
Average Speed = 2xy / (x + y) = (2 * 40 * 60) / (40 + 60) = 4800 / 100 = 48 km/h.

Explanation:
New speed = 3/4 of normal speed => New time = 4/3 of normal time. Difference = 1/3 of normal time = 10 minutes. Normal time = 10 * 3 = 30 minutes.

Explanation:
Let each third of the distance be 60 km. Total distance = 180 km. Total time taken = 60/20 + 60/30 + 60/60 = 3 + 2 + 1 = 6 hours. Average speed = 180 / 6 = 30 km/h.