Task: Question Answering
Input (English): Problem: a train is travelling at 48 kmph . it crosses another train having half of its length , travelling in opposite direction at 42 kmph , in 12 seconds . it also passes a railway platform in 45 seconds . what is the length of the platform ? 
Options: a ) 400 m , b ) 500 m , c ) 600 m , d ) 550 m , e ) 700 m
Output (English): a