Task: Question Answering
Input (English): Problem: 50 % of major airline companies equip their planes with wireless internet access . 70 % of major airlines offer passengers free on - board snacks . what is the greatest possible percentage of major airline companies that offer both wireless internet and free on - board snacks ? 
Options: a ) 20 % , b ) 30 % , c ) 40 % , d ) 50 % , e ) 70 %
Output (English): d