It is given out of 20 moviegoers 8 people purchased popcorn to eat .
The question is asking to find if a theater has 80 people in it, how many should you expect to have purchased popcorn .
If the number of moviegoers increases then expected people who will buy popcorn will also increase.
We can form a proportion.Let x be the number of people who will buy popcorn when moviegoers are 80 in number.

Cross multiplying
20x=80(8)
20x=640
Dividing by 20 both sides
x= 32.
Option C that is 32 is the right answer.