A train passes a platform in 42 seconds and a man standing on the platform in 25 seconds. If the speed of the train is 72 km/hr, what is the length of the platform?
- A300 m
- B270 m
- C340 m
- D370 m
Solution & Step-by-step Explanation
First, convert the speed of the train from km/hr to m/s:
Speed=72×
18
5
=20 m/s
When the train passes a man standing on the platform, it covers a distance equal to its own length (L).
Distance=Speed×Time
L=20×25=500 m
When the train passes the platform, it covers a distance equal to the sum of its own length (L) and the length of the platform (P).
Total Distance=L+P=Speed×Time
500+P=20×42
500+P=840
P=840−500=340 m
Therefore, the length of the platform is 340 m.
Speed=72×
18
5
=20 m/s
When the train passes a man standing on the platform, it covers a distance equal to its own length (L).
Distance=Speed×Time
L=20×25=500 m
When the train passes the platform, it covers a distance equal to the sum of its own length (L) and the length of the platform (P).
Total Distance=L+P=Speed×Time
500+P=20×42
500+P=840
P=840−500=340 m
Therefore, the length of the platform is 340 m.