Task: Question Answering
Input (English): Problem: a certain lab experiments with white and brown mice only . in one experiment , 4 / 9 of the mice are brown . if there are 20 brown mice in the experiment , how many mice in total are in the experiment ? 
Options: a ) 32 , b ) 26 , c ) 36 , d ) 28 , e ) 24
Output (English): c