A train with a uniform speed passes a platform, 122 metres

A train with a uniform speed passes a platform, 122 metres long, in 17 seconds and a bridge, 210 metres long, in 25 seconds. The speed of the train is

Let the length of the train be x
According to the question,

x + 122	=	x + 210
17	=	25

⇒ 25x + 3050 = 17x + 3570
⇒ 25x – 17x = 3570 – 3050
⇒ 8x = 520

⇒ x =	520	= 65 metres
	8

∴ Speed of the train =	65 + 122
	17

=	187	metre/second
	17

= 11 metre/second

=	11 × 18	kmph
	5

= 39.6 kmph