Task: Question Answering
Input (English): Problem: the average weight of a , b and c is 45 kg . if the average weight of a and b be 40 kg and that of b and c be 47 kg , then the weight of b is : 
Options: a ) 39 kg , b ) 32 kg , c ) 33 kg , d ) 34 kg , e ) none of these
Output (English): a