A 270 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train?
Aptitude
Problems on Trains
Difficulty: Medium
Choose an option
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A260 m
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B250 m
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C230 m
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D210 m
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ENone of these
Answer
Correct Answer: 230 m
Explanation
We are given the following:
- Train A length = 270 meters
- Train A speed = 120 km/h
- Train B speed = 80 km/h
- Time to cross each other = 9 seconds
- Trains are moving in opposite directions
Step 1: Convert speeds to m/s Train A speed = 120 × (5 / 18) = 33.33 m/s Train B speed = 80 × (5 / 18) = 22.22 m/s
Step 2: Relative speed Relative speed = 33.33 + 22.22 = 55.55 m/s
Step 3: Total distance covered while crossing Distance = Relative speed × Time = 55.55 × 9 = 500 meters
Step 4: Subtract length of first train to get second train length Other train length = 500 – 270 = 230 meters
Answer: The length of the other train is 230 meters.