Task: Question Answering
Input (English): Problem: a man swims downstream 60 km and upstream 40 km taking 4 hours each time ; what is the speed of the current ? 
Options: a ) 3 kmph , b ) 2.5 kmph , c ) 13 kmph , d ) 6.5 kmph , e ) 7 : 3 kmph
Output (English): b