Problems on Trains – Train length from pole time and speed: A train runs at 36 km/h and takes 8 seconds to pass a pole. What is the length of the train?
Aptitude
Problems on Trains
Difficulty: Easy
Choose an option
-
A288 meters
-
B45 meters
-
C48 meters
-
D80 meters
-
E60 meters
Answer
Correct Answer: 80 meters
Explanation
Introduction / Context:Passing a pole means covering the train’s length at the given speed. Convert speed to m/s to multiply by time and obtain length in metres.
Given Data / Assumptions:
- Speed = 36 km/h = 10 m/s.
- Time = 8 s.
- Pole is a point.
Concept / Approach:L_train = speed (m/s) * time (s).
Step-by-Step Solution:L = 10 * 8 = 80 m.
Verification / Alternative check:Converting back: 80 m at 10 m/s takes 8 s, matching the given time.
Why Other Options Are Wrong:45, 48, 60, 288 m do not equal v * t with v = 10 m/s and t = 8 s.
Common Pitfalls:Leaving speed in km/h and multiplying by seconds directly without conversion.
Final Answer:80 meters