Question

A train passes a station platform in $36$ seconds and a man standing on the platform in $20$ seconds. If the speed of the train is $54$ km/hr, what is the length of the platform ?

Answer 1

Speed = $(54\times \frac{5}{18})$ m/sec = 15 m/sec
Length of the train = $(15\times 20)m=300m$
Let the length of the platform be x metres
Then $\frac{x+300}{36}=15$
$\Rightarrow x+300=540$ $\Rightarrow$ x = 240 m