A train 250 m long takes 15 seconds to cross a man who is walking in the same direction at 4 km/hr. What is the speed of the train?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 64 km/hr
To cross a man, the train covers its own length. When both move in the same direction, the train gains on the man at the difference of their speeds.
Relative speed \(\displaystyle =\frac{250}{15}=\frac{50}{3}\) m/s
In km/hr: \(\displaystyle \frac{50}{3}\times\frac{18}{5}=60\) km/hr
Speed of the train \(-\,4=60\), so speed of the train \(=60+4=64\) km/hr