Task: Question Answering
Input (English): Problem: in a survey of political preferences , 78 % of those asked were in favour of at least one of the proposals : i , ii and iii . 50 % of those asked favoured proposal i , 30 % favoured proposal ii , and 20 % favoured proposal iii . if 5 % of those asked favoured all 3 of the proposals , what x percentage of those asked favoured more than one of the 3 proposals . 
Options: a ) 10 , b ) 12 , c ) 17 , d ) 22 , e ) 30
Output (English): c