A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Aptitude
Problems on Trains
Difficulty: Easy
Choose an option
-
A42 s
-
B40 s
-
C45 s
-
D36 s
Answer
Correct Answer: 40 s
Explanation
Given Data
- Train length = 360 m
- Bridge length = 140 m
- Train speed = 45 km/hr
- Required: time to pass the bridge completely
Step 1: Total distance to be coveredDistance = train length + bridge length = 360 + 140 = 500 m
Step 2: Convert speed to m/s45 km/hr = 45 × (5/18) = 12.5 m/s
Step 3: Time = distance ÷ speedt = 500 ÷ 12.5 = 40 s
Checks & Common Pitfalls
- When crossing a bridge or platform, add lengths.
- Do not forget to convert km/hr to m/s by multiplying by 5/18.
- Check arithmetic: 500/12.5 equals 40.
Final AnswerThe train will pass the bridge in 40 s.