Question 690468
A train running at 60 kmph takes 30 seconds to pass a platform.
 It takes 18 seconds to pass a person walking at 7 kmph in the same direction in which the train is running.
 What is the length of the railway platform and also the length of the train.
:
The effective speed between the train and the walker: 60-7 = 53 km/hr
How long a train takes 18 sec to pass a point at 53 km/hr? (In meters)
d = {{{18/3600}}} * 53 * 1000 
d = 265 meters is the length of the train
:
Find the speed of the train in meter/sec
{{{(60*1000)/3600}}} = 16.67 m/sec
:
Find the length of the platform (p) in meters
Write a time equation, dist/speed = time
{{{(p+265)/16.67}}} = 30
p + 265 = 16.67(30)
p + 265 = 500
p = 500 - 265
p = 235 meters is the length of the platform