A 350 metres long train running at the speed of 200 kmph crosses another train…
2023
A 350 metres long train running at the speed of 200 kmph crosses another train running in opposite direction at the speed of 100 kmph in 15 seconds. What is the length of the other train?
- A.
900 m
- B.
950 m
- C.
825 m
- D.
925 m
Attempted by 16 students.
Show answer & explanation
Correct answer: A
Step 1: Convert speeds from km/h to m/s.
200 km/h = 200 × 5/18 = 1000/18 ≈ 55.56 m/s
100 km/h = 100 × 5/18 = 500/18 ≈ 27.78 m/s
Step 2: Find relative speed (trains moving in opposite directions: add speeds).
Relative speed = 55.56 + 27.78 ≈ 83.33 m/s (exactly 250/3 m/s).
Step 3: Distance covered when crossing = relative speed × time.
Distance = (250/3) × 15 = 250 × 5 = 1250 m.
Step 4: Subtract the known train length to get the other train's length.
Other train length = 1250 − 350 = 900 m.
Answer: 900 m