Data Sufficiency
This topic covers sufficiency decisions, relevance of information, quantitative conditions, statement testing, and deciding when data is enough to answer a problem.
How to study for the GMAT
Build every answer around the exact decision: problem setup, argument gap, passage support, data source, sufficiency, table filter, graph label, or linked two-part condition.
Core concepts
Concept 1
Data Sufficiency questions test the reasoning and decision skills used on the current GMAT exam.
Exam cue: Name the task type: problem solving, reading comprehension, critical reasoning, data sufficiency, multi-source reasoning, table analysis, graphics interpretation, or two-part analysis.
Concept 2
The strongest answer identifies the business-relevant task, data source, argument relationship, arithmetic setup, or decision criterion before comparing choices.
Exam cue: Check constraints, units, variables, claim structure, source tabs, table filters, graph axes, and whether the answer is enough to make the decision.
Concept 3
Eliminate choices that answer a different question, overlook a condition, misuse a source, ignore sufficiency, or rely on specialized outside knowledge.
Exam cue: Use review and edit time to verify the exact question, not just the topic that first looked familiar.
Risk pitfalls and guardrails
Solving a nearby math or reading task while missing the decision the item actually asks for.
Guardrail: Use a 15-second safety pause before finalizing your action.
Using outside business knowledge instead of the evidence, data, or argument in the prompt.
Guardrail: Use a 15-second safety pause before finalizing your action.
Ignoring GMAT-specific constraints such as no calculator in Quant and sufficiency rather than calculation in Data Insights.
Guardrail: Use a 15-second safety pause before finalizing your action.
Memory anchors
Sufficiency
Sufficiency asks whether information is enough, not necessarily what the answer is.
Statement One
Statement one should be tested alone before combining information.
Statement Two
Statement two should be tested alone before combining information.
Together
Statements together may be sufficient even when each alone is not.
Relevant Data
Relevant data narrows possible answers to one outcome.
Insufficient
Insufficient data allows multiple valid answers.
Case Testing
Case testing checks whether different values satisfy the data.
Question Stem
The question stem defines what must be determined.
Hidden Constraint
A hidden constraint in the stem can change sufficiency.
No Full Solve
A full solve is unnecessary when sufficiency is already clear.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
What is the value of x? (1) 2x + 3 = 11 (2) x is positive Which statement best describes the sufficiency of the information?
What is the value of xy? (1) x + y = 10 (2) x = y Which statement best describes the sufficiency of the information?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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