Q1: A train travelling at 48 kmph completely crosses another train having half its length and travelling in opposite direction at 42 kmph, in 12 seconds. It also passes a railway platform in 45 seconds. The length of the platform is
A 450 m
B 600 m
C
400 m
D 560 m
ANS:A -
400 m
Let the length of the first train be x metres.
Then, the length of the second train is
x
metres.
2
Relative speed = (48 + 42) kmph =
90 x
5
m/sec = 25 m/sec.
18
[x + (x/2)]
= 12 or
3x
= 300 or x = 200.
25
2
Length of first train = 200 m.
Let the length of platform beymetres.
600 + 3