Answer ?Anonymous wrote:In a group of 30 students, 8 are enrolled in an English class and 16 are enrolled in an Algebra class. How many students are enrolled in both an English and an Algebra class?
(1) 20 are enrolled in exactly one of these two classes.
(2) 3 are not enrolled in either of these classes.
Use formula:
total = first group + second group + neither group - both groups
=> 30 = 8 english + 16 algebra + neither - both
(1) gives us nothing, NS
(2) gives us the number of students enrolled in neither english nor algebra... which if plugged into the equation above, gives us 'both' as 3.
Hence Sufficient.
