Task: Question Answering
Input (English): Problem: in a group of 90 students , 36 are taking history , and 32 are taking statistics . if 57 students are taking history or statistics or both , then how many students are taking history but not statistics ? 
Options: a ) 9 , b ) 19 , c ) 25 , d ) 27 , e ) 31
Output (English): c