GMAT Data Sufficiency strategies
Data Sufficiency never asks you to solve. It asks whether the two statements provided give you enough information to answer the question. These strategies cover the sufficiency mindset, the fixed five answer choices, the trap of solving instead of evaluating, and a step-by-step walkthrough you can follow on every item.
The core principle
You are evaluating whether the statements provide enough information, not solving for a value. The question stem tells you what you would need to find. Each statement is a piece of evidence. Your job is to decide if the evidence is sufficient, alone or together, to produce one definite answer. You never need the actual number. If a stem asks for the value of and Statement (1) gives , you do not need to compute . Knowing that pins to a single value is enough. Sufficiency is about uniqueness, not arithmetic.
The most common trap
Solving the equation instead of checking sufficiency
The instinct is to compute the answer and pick the choice that matches. Data Sufficiency never rewards the calculation. You can spend thirty seconds solving for a value the question never asks you to produce. The answer choices test your judgment about whether the statements are enough, not whether you can do the arithmetic. Stop at sufficiency. If a statement yields exactly one value, it is sufficient. If it yields two values or none, it is not.
Step-by-step strategy
When to use: every Data Sufficiency question, which is roughly one third of the Data Insights section.
- 1Read the question stem and identify exactly what you would need to answer. Note whether it asks for a value or a yes/no.
- 2Check Statement (1) alone. Forget Statement (2) exists. Decide if (1) alone gives one definite answer.
- 3Check Statement (2) alone. Forget Statement (1). Decide if (2) alone gives one definite answer.
- 4If neither is sufficient alone, combine them. Decide if the two together yield one definite answer.
- 5Map your result to the fixed answer choices. The five choices are always the same: A is (1) alone, B is (2) alone, C is both together, D is each alone, E is neither alone nor together.
When not to use: never. Every Data Sufficiency question uses this fixed framework.
Related pages
Ready to put these strategies to work?
Study the savvy way with unlimited adaptive GMAT-style questions, exact feedback, and full-length exams at peak difficulty. Your first full-length practice test is free.