76. 100 students are majoring in math, business, or both. 72% of the students are business majors, and 58% are math majors. How many students are majoring in both?
76. If 72% are business majors, then 28% are not. If 58% are math majors, then 42% are not. So 28 +42, or 70% of the students, are not majoring in both. So 30% or 30 students are majoring in both.