Task: Question Answering
Input (English): Problem: a train of length l is traveling at a constant velocity and passes a pole in t seconds . if the same train travelling at the same velocity passes a platform in 2 t seconds , then what is the length of the platform ? 
Options: a ) 0.5 l , b ) l , c ) 1.5 l , d ) 2 l , e ) 3
Output (English): b