Out of 36 people in a parade, 18 are wearing red, 15 are wearing blue, and 7 are wearing both red and blue. How many people were wearing neither color?

3 people were wearing neither color.

Step-by-step explanation:

Red: 18/36

Blue: 15/36

Both: 7/36

Neither: ?

Both does not matter here because it does not help us find the answer to neither.

Add the red and blue together:

18/36 + 15/36

33/36

33 people are wearing red and/or blue. That leaves 3 people left over (36 - 33 = 3) who are not wearing either color.