Question

in a group of 60 students, 18 students take Algebra 1, 20 students take Algebra 2, and 10 students take both subjects. How many students don't take either of these subjects?

Answer 1

60 - 18 - 20 - 10

Answer 2

10 take both, so this goes in the very center in the overlapping region

Answer 3

"18 students take Algebra 1" and "10 students take both subjects"

so 18-10 = 8 students take algebra 1 only