RBI Assistant Model Paper 7

Time taken by train to cross a pole
=

1

1200

×60×60 = 3 sec.
When speed is constant then ratio of time taken is directly proportional to Distance covered
So, Ratio of length of train to length of (train + tunnel)
⇒ 3:10
Let length of train = 3x
Length of tunnel = 10x−3x = 7x
ATQ,
7x−3x = 200
4x = 200
So, 3x = 150 meter
Speed of train =

150

3

= 50 m/sec.