Task: Question Answering
Input (English): Problem: in one hour , a boat goes 15 km / hr along the stream and 9 km / hr against the stream . the speed of the boat in still water ( in km / hr ) is : 
Options: a ) 12 kmph , b ) 13 kmph , c ) 14 kmph , d ) 15 kmph , e ) 16 kmph
Output (English): a