There are 8 students in the class in art. If 40% of the class is in art club. How many students are in class in all?
To find the total number of students in the class, we need to determine what percentage the students in the art club represent of the entire class.
If 40% of the class is in the art club, then 100% - 40% = 60% of the class is not in the art club.
Since the ratio of students in the art club to the total class size is 40%/100% = 4/10,
then the total class size must be 8 students / (4/10) = 8 * (10/4) = <<8*(10/4)=20>>20 students. Answer: \boxed{20}.