Task: Question Answering
Input (English): Problem: how many liters of a 40 % iodine solution need to be mixed with 35 liters of a 20 % iodine solution to create a 30 % iodine solution ? 
Options: a ) 30.5 , b ) 49 , c ) 100 , d ) 105 , e ) 140
Output (English): a