A train 150 metres long takes 20 seconds to cross a platform 450 metres long. The speed of the train in, km per hour is :

Solution (By Examveda Team)

$$\eqalign{ & {\text{Speed of train :}} \cr & = \frac{{450 + 150}}{{20}} \cr & = 30{\text{ m/s}} \cr & {\text{Speed (in km/hr):}} \cr & = 30 \times \frac{{18}}{5} \cr & = 108{\text{ km/hr}} \cr} $$