Question

A train is running at a speed of $45$ km/hr and a man is walking at a speed of $5$ km/hr in the opposite direction. If the train crosses the man in $18$ seconds then what is its length ?

• A. $200$ m
• B. $220$ m
• C. $180$ m
• D. $250$ m

Answer 1

The correct option is D $250$ m

Since the man is walking in the opposite direction of the moving train
Relative speed of the train =$(45+5)$ km/hr $=$ $(50\times \frac{5}{18})$ m/sec $=\frac{250}{18}$ m/sec
Length of the train $=$ Relative speed $\times$ Time taken in crossing the man
$=(\frac{250}{18}\times 18)m=250$ m