There are 30 students in a classroom. Eighteen students read A Wrinkle in Time while 22 children read The Hobbit. If all children read at least one of the books, how many read both books?
30 - 18 = 12 students read the Hobbit only
30 - (12 + 8) = 10 students who read both
30 - 18 = 12 students read the Hobbit only
30 - (12 + 8) = 10 students who read both