Multiple choice

Two trains are running at 72 km/h and 48 km/h in the same direction. The faster train completely passes a man, sitting in the slower train, in 15 sec. Find the length of the faster train.

  1. 86 m

  2. 110 m

  3. 100 m

  4. 95 m

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Relative speed = 72 - 48 = 24 km/h. Convert to m/s: 24 * (5/18) = 20/3 m/s. Length of train = speed * time = (20/3) * 15 = 100 m.

AI explanation

Using the relative speed formula for objects moving in the same direction, the relative speed is 72 km/h minus 48 km/h, which equals 24 km/h. Converting this to m/s by multiplying by 5/18 gives 20/3 m/s. The length of the faster train is the relative speed multiplied by the time taken to pass the man, so (20/3) times 15 equals 100 m. The length of the train is 100 m.

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