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
Answer: Option A
Let the length of the first train be x metres.
Length of first train = 200 m.
Let the length of platform be y metres.
600 + 3y = 1800
y = 400 m.