Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Jun 1006:00 AM PDT
-06:15 PM PDT
Register for the GMAT Club Virtual MBA Spotlight Fair – the world’s premier event for serious MBA candidates. This is your chance to hear directly from Admissions Directors at nearly every Top 30 MBA program..- Jun 10
10:00 AM PDT
-11:00 AM PDT
Scoring 715 on the GMAT Focus Edition requires more than just learning formulas, memorizing concepts, or solving hundreds of questions. In this episode, Nishant shares how he improved his GMAT preparation by focusing on application of concepts, and more. 
Jun 1111:00 AM EDT
-01:00 PM EDT
TTP GMAT OnDemand gives serious students 400+ hours of expert video instruction, the full TTP course, AI support, weekly office hours, and a 715+ score guarantee—all built for elite GMAT score improvement.
Jun 2207:30 PM EDT
-09:30 PM EDT
Master the GMAT with expert live instruction, a personalized study plan, and real-time support. Includes 40 hours of online classes plus 6 months of access to the TTP GMAT OnDemand video course. Class date: Mon/Wed June 22, 2026 →August 26, 2026
18 Dec 2025, 09:00
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
65%
(hard)
Question Stats:
55% (01:14) correct
45%
(01:29)
wrong
based on 236
sessions
History
Date
Time
Result
Not Attempted Yet
At a certain university, each of two advanced courses, Biology and Chemistry, has more than 25 students enrolled. Is there at least one student enrolled in both courses?
(1) Every student who is not enrolled in Biology is also not enrolled in Chemistry.
(2) Every student enrolled in Chemistry is also enrolled in Biology.
I31-08
(1) Every student who is not enrolled in Biology is also not enrolled in Chemistry.
(2) Every student enrolled in Chemistry is also enrolled in Biology.
I31-08
12 Days of Christmas Competition
This question is part of our holiday event
Win $40,000 in prizes: courses, tests, and more
18 Dec 2025, 10:00
Kudos
Bookmarks
GMAT Club Official Explanation:
At a certain university, each of two advanced courses, Biology and Chemistry, has more than 25 students enrolled. Is there at least one student enrolled in both courses?
(1) Every student who is not enrolled in Biology is also not enrolled in Chemistry.
This means anyone in Chemistry must also be in Biology because if a student were in Chemistry but not in Biology, then that student would be a counterexample to the statement. Since such a student cannot exist, all students in Chemistry must also be in Biology. So every Chemistry student is also in Biology. Since Chemistry has more than 25 students, at least those 25+ students are definitely in both courses. Sufficient.
(2) Every student enrolled in Chemistry is also enrolled in Biology.
This says the same thing: anyone in Chemistry must also be in Biology because if someone belonged to Chemistry without belonging to Biology, the condition would be violated. Therefore every Chemistry student must already be a Biology student. So again, every Chemistry student is in both courses. Since Chemistry has more than 25 students, there are definitely students in both. Sufficient.
Answer: D.
General Discussion
18 Dec 2025, 09:21
Kudos
Bookmarks
I. If a student is in Chemistry, then they must be in Biology. Since Chemistry has more than 25 students, all of them are also in Biology, so there is overlap.
Sufficient
II. Every Chemistry student is enrolled in Biology. Chemistry has more than 25 students, so those students are also in Biology. Overlap exists.
Sufficient
Answer: D
Sufficient
II. Every Chemistry student is enrolled in Biology. Chemistry has more than 25 students, so those students are also in Biology. Overlap exists.
Sufficient
Answer: D
