Jim and holly are making gingerbread men. it takes them both 2 minutes to make 2 gingerbread shapes. at this rate, how many people are needed to make 400 gingerbread men in 400 minutes?

The answer is 2 person. The relation for 2 persons is as following: 2 minutes = 2 gingerbread men. If those 2 persons want to make 400 gingerbread men, they will need x minutes. So: 2 minutes : 2 gingerbread men = x : 400 gingerbread men. x = 2 minutes * 400 gingerbread men : 2 gingerbread men = 400 minutes. In other words, 2 persons will make 400 gingerbread men in 400 minutes.

The variables should add up to equal 1