Official Guide Explanation:
Data Sufficiency #4

Background

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Solution and Metadata

Question: 4
Page: 273
Difficulty: 5 (Moderate)
Category 1: Word Problems > Sets >
Category 2: Arithmetic > Sets > 2 sets

Explanation: Since the question is somewhat elliptical, first try to understand what it's asking. Presumably, there are some students in a chemistry course, some students in a biology course, and some students who are not in either one. The question wants to know whether there are more students in both courses than the number in neither course.

Statement (1) is not sufficient. The number of students in chemistry doesn't tell us the number in both or the number in neither.

Statement (2) is not sufficient by the same reasoning as (1).

Taken together, the statements are still not sufficient. There could be anywhere between 0 and 60 students enrolled in both courses. And without knowing the total number of students at the college, we don't know how many are enrolled in neither course. Choice (E) is correct.

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