in all cases x/100 is just a way to represent percentage. and since it's the same everywhere, it's not even relevant to decide wich option describes the context right
A) 80/140 is the portion that describes the book readers over all people surveyed
B) 31/63 just 63 people are relevant bc it's specified that we only consider beach travelers.
that also explains the 31, bc that's the number of beach travelers who'd like to watch a movie
C) 15/80 only 80 movie watchers in total, of whom 15 would prefer the city
