GMAT Data Sufficiency Process of Elimination Tips: How to Complete DS Questions in Less than One and Half Minutes

Once GMAT test takers have learned about the fundamental concepts tested in the exam, focus should be on saving time for each question. In GMAT, each question should be answered in just under two minutes. Data sufficiency follows a format where a question is followed by two statements, labeled as (1) and (2), and five answer choices in the format:

a) Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient to answer the question asked.

b) Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question asked.

c) BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked.

d) EACH statement ALONE is sufficient to answer the question asked.

e) Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.

Process of Elimination techniques will allow you to complete the GMAT DS questions in less than one and half minutes.

Let us consider a few scenarios:

Statement 1 is insufficient: When Statement 1 is insufficient; you can eliminate two answer choices: A and D.

Statement 2 is insufficient: When Statement 2 is insufficient; you can eliminate two answer choices: B and D.

Out of the five answer choices, the probability of getting C or E correct is 40%, while getting A, B or D correct is 60%. Therefore, the chances that only one statement will contribute in finding the correct answer choices is 20% higher than the instance where both the statements are used. Keep that in mind, and if you have read our article about how test creators force us to believe that Answer Choice C is the best option, you will start with statement 2, instead of statement 1.

Let us look at an example:

ABCD is a quadrilateral with parallel sides. Is ABCD a rectangle?

(1) AC and BD bisects each other
(2) Sum of <DAB and <BCD is less than 180 degree.

1) Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient to answer the question asked.

2) Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question asked.

3) BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked.

4) EACH statement ALONE is sufficient to answer the question asked.

5) Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.

First, you need to know the properties of a rectangle:

a) Each Angle is 90 Degrees
b) Sum of Opposite Angles is equal to 180 Degree
c) Opposite Sides are Parallel to each other
d) Opposite Sides are Equal
e) Diagonals bisect each other

ABCD is a quadrilateral with parallel sides. Is ABCD a rectangle?

(1) AC and BD bisects each other
(2) Sum of <DAB and <BCD is less than 180 degree.

a) Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient to answer  the question asked.

b) Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question asked.

c) BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked.

d) EACH statement ALONE is sufficient to answer the question asked.

e) Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.

Let us start with Statement (2), as mentioned in our GMAT DS Strategy article.

Statement 2: Sum of <DAB and <BCD is less than 180 degree

Since <DAB and <BCD are opposite angles of the quadrilateral, and the sum is less than 180 degree, it is not a rectangle. When Statement 2 is insufficient, we can eliminate options B and D.

Statement 1: AC and BD bisects each other

We know that Statement 1 is not enough since in a parallelogram the two diagonals bisect each other too.

If we combine the two statements, it becomes clear that ABCD is not a rectangle.