Task: Question Answering
Input (English): Problem: if in one hour , a canoe rows at 16 km / hr downstream and 9 km / hr upstream , calculate the speed of a boat in still water ( in km / hr ) . 
Options: a ) 18 kmph , b ) 15.5 kmph , c ) 12.5 kmph , d ) 13.5 kmph , e ) 22.5 kmph
Output (English): c