Task: Question Answering
Input (English): Problem: a train , 800 meter long is running with a speed of 78 km / hr . it crosses a tunnel in 1 minute . what is the length of the tunnel ( in meters ) ? 
Options: a ) 440 m , b ) 500 m , c ) 260 m , d ) 430 m , e ) 450 m
Output (English): b