Quantitative Comparison is the GRE quant question type that rewards technique over raw calculation. Instead of solving for an answer, you decide which of two quantities is larger, and often you never finish the arithmetic at all. This guide covers the four answer choices, the one rule that eliminates a wrong answer instantly, the plug-in-numbers method, the traps that catch strong math students, and interactive practice with full solutions.
A Quantitative Comparison question shows Quantity A and Quantity B and asks which is greater. The four answer choices never change. The single most useful rule: the answer is "cannot be determined" only when there are variables. If both quantities are plain numbers, the answer must be A, B, or C. The method is to compare, not calculate, and when variables appear, to plug in 0, 1, a negative, and a fraction. The on-screen calculator is available, but comparison usually beats computation.
Most quant questions ask you to find a value. Quantitative Comparison asks a narrower question: which of these two quantities is bigger? You are shown Quantity A and Quantity B, sometimes with a piece of centered information that applies to both, and you choose from four fixed answers. You frequently do not need to compute a final number, only to establish a relationship.
The four answer choices are identical on every question, so memorize them:
| Choice | Meaning |
|---|---|
| A | Quantity A is greater. |
| B | Quantity B is greater. |
| C | The two quantities are equal. |
| D | The relationship cannot be determined from the information given. |
The on-screen calculator is available here, the same one covered in our GRE calculator simulator, but Quantitative Comparison usually rewards comparison over calculation.
Here is the highest-value fact about Quantitative Comparison: choice D, cannot be determined, is only possible when the quantities contain a variable or an unknown. If both quantities are made only of numbers, then one relationship is always true, so the answer has to be A, B, or C. You can cross out D before you do anything else.
The reverse is the real skill. When there is a variable, you cannot trust a single test case. The relationship might hold for the number you tried and flip for another, and the moment it flips, the answer is D.
Work through these four questions. Decide which quantity is greater, then check your answer and read the full solution. Each lands on a different answer choice and shows a different principle.
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Free GRE Score Calculator| Trap | What happens | The fix |
|---|---|---|
| Only testing positive integers | A statement looks true for x = 2, so you pick A or B, but it flips for a negative or a fraction. | Always test 0, 1, a negative, and a fraction before committing. |
| Choosing D on a number-only question | You pick cannot be determined even though both quantities are constants. | With no variable, one relationship is always true. Cross out D immediately. |
| Calculating too far | You compute exact values when a quick comparison would have settled it. | Stop the moment you can see which side is larger. |
| Multiplying both sides by a variable | You multiply or divide by an expression that could be negative, which flips the inequality. | Only apply an operation to both sides when you are certain it is positive. |
Quantitative Comparison rewards the same habits across the whole Quant section, so strong QC work lifts your score directly. To see how raw performance becomes a scaled score, read how GRE section-adaptive scoring works, practice GRE Data Interpretation sets, keep the GRE quant formula sheet handy, and project your result with the GRE score calculator, then sharpen GRE Numeric Entry. Moving on to GRE Verbal? Start with GRE Text Completion.
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GRE Score Calculator Quant Formula SheetThey are fixed on every question: (A) Quantity A is greater, (B) Quantity B is greater, (C) the two quantities are equal, and (D) the relationship cannot be determined from the information given.
Choice D is only possible when the quantities involve variables or unknowns. If both quantities are plain numbers, one relationship is always true, so the answer must be A, B, or C, never D.
Compare rather than calculate: simplify both quantities by doing the same operation to each, then decide which is larger. When variables are involved, plug in strategic numbers including 0, 1, a negative, and a fraction. If different values give different relationships, the answer is cannot be determined.
Yes, the on-screen calculator is available throughout the GRE Quant section. But most QC questions are solved faster by comparison and estimation than by full calculation, so reach for it only when the numbers demand it.
A Problem Solving question asks you to find or calculate a specific answer. A Quantitative Comparison question asks only which of two quantities is greater, or whether that can be determined, so you often never need to compute a final value.
Quantitative Comparison questions appear in both Quantitative Reasoning sections and usually come first in each section. They make up a large share of the quant questions, so they have a real effect on your Quant score.
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