The anatomy every Verbal question assumes
Both CR and the harder RC questions assume you can take an argument apart. An argument offers one or more premises (reasons taken as given) in support of a conclusion (the claim those reasons are meant to establish). Everything else — examples, background, opposing views — is scaffolding.
Find the conclusion first; it is the claim everything else exists to support. It is often not the last sentence, and it hides behind words like therefore, thus, so, clearly, hence. Premises hide behind because, since, for, given that. The conclusion is the one statement the passage argues for but never offers as a reason for anything further.
Locate the parts. "Sales rose 20% after we cut prices. So the price cut caused the increase." Premise: sales rose after the cut. Conclusion: the cut caused it. The leap from "after" to "caused" is the assumption — and almost every CR question lives in exactly that gap.
Two kinds of reasoning — and what each lets evidence do
Deductive arguments aim to guarantee the conclusion: if the premises are true, the conclusion must be true (valid), and a valid argument with true premises is sound. Inductive arguments aim only to make the conclusion probable given the evidence. Crucial consequence: evidence can strengthen or weaken only an inductive argument — you cannot "add evidence" to make a valid deduction more valid.
This is why Strengthen/Weaken CR questions are always about inductive arguments: they turn on whether new information makes the conclusion more or less likely, not on formal validity.
The assumption gap
An assumption is an unstated premise the argument needs to work. Two flavors the GMAT distinguishes:
- Necessary assumption — must be true or the argument collapses. Test it by negation: if denying the statement destroys the argument, it's a necessary assumption.
- Sufficient assumption — if added, it makes the conclusion follow. It may claim more than strictly required.
Confusing necessary with sufficient is the GMAT's favorite logical error. "Watering is necessary for the plant to grow" does not mean "watering is sufficient" (it also needs light). Many flawed-reasoning answer choices describe exactly this swap — or its cousin, treating a correlation as if it proved causation.
The flaws worth recognizing on sight
| Flaw | What happens | Tell |
|---|---|---|
| Correlation ⇒ causation | Two things move together, so one is said to cause the other | ignores other causes / reverse direction |
| Unrepresentative sample | A biased or tiny sample generalized to all | "survey of volunteers," "one store" |
| Percent vs amount | A percentage change mistaken for an absolute one (or vice versa) | shares vs counts |
| Necessary vs sufficient | A required condition treated as a guarantee | "only if" read as "if" |
| Equivocation | A key term shifts meaning mid-argument | the same word, two senses |
| False dilemma | Two options presented as the only ones | "either … or …" |
Before reading the answer choices, say the gap out loud. "It assumes nothing else changed when prices dropped." Naming the weakness yourself turns five tempting options into a quick match-and-eliminate — you're looking for the choice that fills (assumption), widens (weaken), or seals (strengthen) the gap you already found.
Checklist
- Underline the conclusion; bracket the premises
- Decide: is the argument inductive (most CR) or deductive?
- State the assumption gap in your own words
- Test necessary assumptions by negation
- Watch for the six recurring flaws, especially correlation→causation
Sample Questions
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