Task: Question Answering
Input (English): Problem: each of the 20 boxes in a certain shipment weighs either 10 pounds or 20 pounds , and the average ( arithmetic mean ) weight of the boxes in the shipment is 18 pounds . if the average weight of the boxes in the shipment is to be reduced to 16 pounds by removing some of the 20 - pound boxes , how many 20 - pound boxes must be removed ? 
Options: a ) 8 , b ) 10 , c ) 12 , d ) 14 , e ) 15
Output (English): b