Simon knows that 20% of the people at a movie theater are seeing a romantic comedy. How many people are at the movie theater if 55 people are seeing a romantic comedy?

Answer 1

55 are seeing romantic comedy... this is your "part" for numbers of people. The total number at the theater is what we are trying to find so we call it X - this is the "whole" for number of people.

20% of the total are seeing romantic comedy, ... that is the "part" for percentages. The "whole" for percentages is always 100%

Set up your ratios as "part to whole" ... part in the numerator and whole in the denominator.

20/100 = 55/X

and use cross multiplication to solve.