Task: Question Answering
Input (English): Problem: there are 6 people in the elevator . their average weight is 154 lbs . another person enters the elevator , and increases the average weight to 151 lbs . what is the weight of the 7 th person . 
Options: a ) 133 , b ) 168 , c ) 189 , d ) 190 , e ) 200
Output (English): a