Assumption Questions: LSAT & GMAT Practice Quiz (with the Negation Test)
An assumption question asks for the unstated thing an argument needs in order to work. It is one of the highest-frequency types on both the LSAT (Logical Reasoning is now about two-thirds of the scored test) and the GMAT (Critical Reasoning grew after Sentence Correction was removed). Twelve drills below, five choices each. If you are stuck between two options, negate each one: the choice that destroys the argument when negated is the assumption.
0 / 12 answered
Q1
Our online store moved the checkout button to the top of the page in March. Sales rose 14 percent in April. Clearly, the new button placement caused the increase. The argument depends on assuming which of the following?
Q2
City officials note that traffic accidents at Maple Junction fall sharply whenever the streetlights there are working. They have therefore proposed installing brighter streetlights at Maple Junction to reduce accidents further. Which of the following is an assumption on which the proposal depends?
Q3
In a voluntary online poll on our company blog, 78 percent of respondents said they would pay more for a plastic-free version of our product. The marketing team concludes that most of our customers would pay more for a plastic-free version. The conclusion depends on assuming which of the following?
Q4
Last year Northgate Hospital had a higher percentage of successful transplant surgeries than Riverside Hospital did. A health columnist concludes that a patient scheduled for a transplant is more likely to survive at Northgate than at Riverside. Which of the following is an assumption the columnist's conclusion requires?
Q5
A free press is essential to a functioning democracy. Our nation's newspapers are struggling financially. Therefore, to protect our democracy, the government should fund newspapers directly. Which of the following is an assumption on which the argument depends?
Q6
The number of reported burglaries in Kelford rose from 40 last year to 60 this year. A local candidate concludes that Kelford has become a more dangerous place to live. Which of the following is an assumption required by the candidate's reasoning?
Q7
Employees who take all of their allotted vacation days are rated more productive by their managers than employees who take few vacation days. A consultant concludes that requiring employees to use all their vacation days would raise productivity. Which of the following is an assumption on which the consultant's conclusion depends?
Q8
The Larkspur Theater will survive only if it attracts younger audiences. Its new director has scheduled a season of contemporary plays, which surveys show younger theatergoers prefer. The board concludes that the theater will now survive. Which of the following is an assumption the board's conclusion requires?
Q9
A study of 500 adults found that those who ate breakfast daily weighed less on average than those who skipped breakfast. A nutrition columnist advises readers who want to lose weight to start eating breakfast every day. The advice depends on assuming which of the following?
Q10
Every winning entry in the county photography contest over the past decade was shot on film rather than digitally. An aspiring entrant concludes that shooting on film will improve her chances of winning this year. Which of the following is an assumption on which her conclusion depends?
Q11
Since the Fairview Library began opening on Sundays, weekly book loans have risen by 20 percent. The library director argues that extending Saturday hours by three hours would produce a similar rise. Which of the following is an assumption on which the director's argument depends?
Q12
Our software team fixed 30 percent more bugs last quarter than the quarter before, while team size stayed the same. The engineering manager concludes that the team has become more efficient. Which of the following is an assumption the manager's conclusion requires?
Answer all 12 questions to see your result 👆
Assumption questions: the cheat sheet
- The negation test
- Negate an answer choice. If the argument falls apart, that choice is a necessary assumption. If the argument still stands, it is not. This single move settles most two-way splits.
- Necessary vs. sufficient
- A necessary assumption is what the argument cannot live without. A sufficient one would guarantee the conclusion. Assumption questions almost always want the necessary one — so the weaker-sounding answer is usually right.
- Too strong is wrong
- Words like 'only', 'always', 'best' and 'every' usually over-commit. The argument rarely needs that much.
- A premise is not an assumption
- If the choice restates something the argument already said out loud, it is not the unstated thing the argument depends on.
- No alternative cause
- Whenever a conclusion is causal, the argument assumes nothing else produced the effect. This is the single most tested assumption.
- No countervailing effect
- Plan-based arguments assume the plan will not create a side effect that cancels its own benefit.
- Comparable groups
- Any comparison of rates, averages or counts assumes the things compared are alike in the way that matters.
- The future resembles the past
- Arguments from a track record assume the conditions that produced it still hold.
How assumption questions work on the LSAT and GMAT
An assumption question hands you an argument with a hole in it and asks what has to be true — but is never stated — for the argument to hold together. On the LSAT the stem usually reads 'which one of the following is an assumption on which the argument depends'; on the GMAT it reads 'the argument above depends on which of the following assumptions'. The task is identical, and so is the technique.
The reason this type is worth drilling first is arithmetic. LSAC removed Logic Games in August 2024 and replaced that section with a second Logical Reasoning section, so Logical Reasoning now makes up roughly two-thirds of the scored LSAT. On the GMAT Focus Edition, Sentence Correction was removed from Verbal entirely, which leaves Critical Reasoning and Reading Comprehension to divide the section between them. Both exams moved weight toward exactly this skill.
The negation test is the reason assumption questions are tractable. Take the choice you are considering and state its opposite. If the argument still works with the opposite true, the choice was never necessary, and you can eliminate it without further thought. If the argument dies, you have found the load-bearing wall. Applied to a causal argument, negating 'no other change occurred' gives you 'some other change occurred' — and the causal claim immediately loses its support.
The most common way to lose points here is picking an answer that is true and helpful but stronger than required. An assumption is a minimum, not a maximum. If a choice says the plan is the best available option, ask whether the argument ever claimed that; usually it claimed only that the plan would work. The correct answer to an assumption question often sounds underwhelming, and that is precisely why it survives negation.
Assumption questions FAQ
What is an assumption question?
A question that asks for something the argument needs to be true but never states. It is not asking what would help the argument most — it is asking what the argument cannot survive without.
How does the negation test work?
Negate the answer choice and reread the argument. If the argument collapses, the choice is a necessary assumption. If the argument is unaffected, eliminate it. Use it whenever you are down to two options.
What is the difference between a necessary and a sufficient assumption?
A necessary assumption must be true for the argument to work. A sufficient assumption, if added, would make the conclusion follow completely. LSAT 'assumption' questions and GMAT assumption questions almost always want the necessary one, which is why the correct answer usually sounds weaker than the tempting one.
Are assumption questions the same on the LSAT and the GMAT?
The skill is the same and the technique transfers directly. GMAT Critical Reasoning arguments tend to be business-flavored and slightly shorter; LSAT Logical Reasoning arguments cover a wider range of subjects and push harder on the necessary-versus-sufficient distinction.
Are these real LSAT or GMAT questions?
No. Official questions are copyrighted by LSAC and GMAC. These are original arguments written in the style of both exams, using the same flaw patterns and the same distractor traps.
How many assumption questions appear on each exam?
Assumption is among the most frequent Logical Reasoning types on the LSAT and among the most frequent Critical Reasoning types on the GMAT. Exact counts vary by form, but on both exams it is a type you can expect to see several times.