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 6 t seconds , then what is the length of the platform ? 
Options: a ) l , b ) 3 l , c ) 5 l , d ) 7 l , e ) 9 l
Output (English): c