150 meter long train takes 10 second two pass a man who is going in same direction at the speed of 2 km/hr . What is the speed of the train?

Let the speed of the train be Y km/hr
∴ length of the train = 150 m
= 150/1000 = 3/20 km.
Time taken to cross the man = 10 seconds
= 10/ (60 x 60) = 1/360 hrs .
∵ time = Length of the train /( speed of the train - speed of the man )
∴ 1/360 = ( 3 / 20) / ( Y - 2)
⇒ (Y - 2 ) = 3/20 x 360
⇒ (Y - 2 )= 54
⇒ Y = 54 + 2
= 56 km/hr.