A train runs at 60 km/h and passes completely through a tunnel 1.5 km long in 2 minutes. What is the length of the train (in metres)?
Aptitude
Time and Distance
Difficulty: Easy
Choose an option
Answer
Correct Answer: 500 m
Explanation
Introduction / Context:While passing a tunnel, the train’s front travels train_length + tunnel_length. Use distance = speed * time (consistent units) to find the distance covered in the 2-minute interval, then subtract the tunnel length to get the train length.
Given Data / Assumptions:
- Speed = 60 km/h.
- Tunnel length = 1.5 km.
- Time = 2 min = 1/30 h.
Concept / Approach:Total distance covered in time T: S = v * T. Train length = S − tunnel_length (in km), then convert to metres.
Step-by-Step Solution:
S = 60 * (1/30) = 2 km.Train length = 2 − 1.5 = 0.5 km = 500 m.Verification / Alternative check:At 60 km/h, 2 minutes corresponds to 2 km—consistent.
Why Other Options Are Wrong:250/1000/1500 m imply tunnel pass times other than 2 minutes.
Common Pitfalls:Using only tunnel length instead of tunnel + train while timing.
Final Answer:500 m