In a class of 25 students, 12 are wearing a white shirt and 15 are wearing black shoes. what is the percentage of students that have both?
12 + 15 - 25 = 27 - 25 = 2 are wearing both
12 - 2 = 10 wear white shirts only
15 - 2 = 13 wear black shoes only
2 + 10+ 13 = 25
The % wearing both is 2 / 25 = 8 / 100 = 8%
12+15=27
27-25=2 people but we want to know the percent
2/25=0.08=8%
+14 
