Q175
ArithmeticSpeed, Time & Distance
A person, standing on a railway platform 120 meters long, notices that a train, which passed him in 5 seconds, passed completely through the station in 15 seconds. The length of the train is
- a.50 m
- b.60 m
- c.100 m
- d.55 m
Answer: (B) 60 m
Let the train's length be $x$ m. Its speed is $\dfrac{x}{5}$ (passing the person) and also $\dfrac{x+120}{15}$ (passing the whole platform). Setting these equal: $15x=5(x+120)$, giving $x=60$ m.