Data Sufficiency trips up more GMAT test takers than any other question type, because it asks something unusual: not to solve the problem, but to decide whether it can be solved. This guide covers the five answer choices, the AD/BCE grid that makes them fast, the difference between value and yes/no questions, the traps that catch strong quant students, and interactive practice with full solutions.
A Data Sufficiency question gives you a question and two statements, and asks whether the statements provide enough information to answer, not what the answer is. The five answer choices never change. Evaluate each statement alone first, then together only if needed, using the AD/BCE grid. Watch two things: a no answer still counts as sufficient on yes/no questions, and you must never carry information from one statement into the other. On the GMAT Focus Edition, Data Sufficiency now sits inside the Data Insights section.
Most quant questions ask you to find an answer. Data Sufficiency asks a different question: do you have enough information to find the answer at all? You are given a question, then two numbered statements, and your job is to decide which statement or statements are sufficient to answer it. You almost never need to finish the calculation.
The five answer choices are identical on every Data Sufficiency question, so commit them to memory:
| Choice | Meaning |
|---|---|
| A | Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. |
| B | Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. |
| C | BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. |
| D | EACH statement ALONE is sufficient. |
| E | Statements (1) and (2) TOGETHER are NOT sufficient. |
On the GMAT Focus Edition, Data Sufficiency questions appear in the Data Insights section rather than the Quantitative section, but the format and answer choices are unchanged from the classic GMAT.
The five choices look fiddly, but a simple elimination method collapses them into two quick decisions. Start by testing Statement (1) alone:
Then test Statement (2) alone, never using anything from Statement (1):
| Statement (1) | Statement (2) | Answer |
|---|---|---|
| Sufficient | Sufficient | D |
| Sufficient | Not sufficient | A |
| Not sufficient | Sufficient | B |
| Not sufficient | Not sufficient | C or E (test them together) |
Only when both statements fail alone do you combine them: if together they answer the question, the answer is C; if even together they cannot, it is E. This order matters, because testing statements together too early is the single most common way strong quant students lose easy points.
Every Data Sufficiency question is one of two kinds, and sufficient means something slightly different in each.
A value question asks for a specific quantity, like What is the value of x? A statement is sufficient only if it narrows the answer to exactly one value. If a statement leaves two or more possibilities, it is not sufficient. For example, \(x^2 = 16\) is not sufficient to find x, because x could be 4 or -4.
A yes/no question asks something answerable with yes or no, like Is x greater than 10? Here a statement is sufficient if it forces a definite yes or a definite no. This is where careful students slip: a statement that guarantees the answer is no is just as sufficient as one that guarantees yes. Sufficiency is about certainty, not about the answer being positive.
Work through these four questions using the AD/BCE grid. Select your answer, then check it and read the full solution. Each one lands on a different answer choice and demonstrates a different trap.
Enter your three section scores and instantly project your GMAT Focus total and percentile.
Free Score Calculator| Trap | What happens | The fix |
|---|---|---|
| Solving too far | You calculate the actual answer instead of just deciding sufficiency, burning time you do not have. | Stop the moment you know a unique answer exists. |
| Carrying information across statements | You let a fact from Statement (1) shape how you judge Statement (2). | Reset completely between statements. Judge each in isolation. |
| The C-trap | The statements look built to combine, so you pick C without checking whether one alone already works. | Always test each statement alone first. Reach for C only after both fail. |
| Forgetting a no is sufficient | On yes/no questions you mark a statement insufficient because the answer turns out to be no. | A definite no answers the question. Sufficiency means certainty, not a yes. |
A fifth, quieter trap: assuming numbers are positive integers when the question never said so. Unless a variable is restricted, it can be negative, zero, or a fraction, and testing those cases is often what separates a sufficient statement from an insufficient one.
Because Data Sufficiency now sits inside Data Insights, strong DS skills lift one of the three scored sections directly. For how that section is scored and what a good score looks like, see the Data Insights guide, and to model your total, use the GMAT Focus score calculator. For the other Data Insights types, see Table Analysis, Graphics Interpretation, and Two-Part Analysis.
Model any mix of section scores with the free PrepDrills calculator, or go deeper on the section Data Sufficiency belongs to. No signup required.
Open the Calculator Data Insights GuideYes. Data Sufficiency remains a core GMAT question type, but on the GMAT Focus Edition it appears inside the Data Insights section rather than the Quantitative section. The format and the five answer choices are unchanged from the classic GMAT.
They are fixed on every question: (A) statement 1 alone is sufficient, (B) statement 2 alone is sufficient, (C) both statements together are sufficient but neither alone, (D) each statement alone is sufficient, and (E) the two statements together are still not sufficient.
It is an elimination shortcut. Test Statement (1) first: if it is sufficient, the answer is A or D; if it is not, the answer is B, C, or E. Then test Statement (2) alone to choose between the remaining options. It turns five answer choices into two quick decisions.
Yes. On a yes/no Data Sufficiency question, a statement is sufficient if it produces a definite answer, whether that answer is yes or no. Sufficiency is about certainty, not about the answer being positive.
No. Each statement must be judged completely on its own. Carrying a fact from Statement (1) into your evaluation of Statement (2) is one of the most common Data Sufficiency mistakes and leads to wrong answers.
A value question asks for a specific quantity and needs a statement that narrows it to exactly one value. A yes/no question asks something answerable with yes or no and needs a statement that forces a definite yes or a definite no.
Project your score with the free PrepDrills tool, or connect with an Epic Exam Prep tutor for personalized one-on-one coaching on Data Insights and the rest of the GMAT Focus.
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