A train 150 metre long takes 20 seconds to cross a platform

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

Speed of train =	length of platform and train
	Time taken in crossing

=		450 + 150		m/sec.
		20

=		600		m/sec.
		20

=		30 ×	18		kmph
			5

= 108 kmph.