Critical Reasoning questions give you a short argument, usually under 100 words, and ask you to do something with its logic: weaken it, strengthen it, find the assumption it depends on, explain a surprising result, or spot its flaw. They are a large part of the GMAT Focus Verbal Reasoning section, so steady accuracy here pays off.
Read the question stem first, so you know what you are reading for. Then split the argument into its conclusion and its evidence, and ask what gap connects them. Most arguments jump from evidence about one group, period or measure to a conclusion about another. That gap is where the answer lives: a weakener widens it, a strengthener narrows it, and an assumption bridges it.
The wrong choices follow patterns. Some are true but irrelevant, some touch the topic but not the conclusion, and some are too extreme to be required. Watch for scope shifts: an argument about waiting times does not care about customer satisfaction, and an argument about one company does not care about its competitors. Judge each choice against the conclusion, not against the topic.
The five questions below cover weaken, strengthen, paradox, assumption and flaw questions, with a reason given for every answer choice.
5 practice questions
Critical ReasoningWeaken ArgumentEasy
Question 1
Last year Brightwell Grocers installed self-checkout kiosks in 20 of its 40 stores. Over the following six months, the average time customers waited at checkout in those 20 stores fell by 30 percent, while waiting times in the other 20 stores did not change. Brightwell's operations director concludes that installing kiosks in the remaining 20 stores will reduce checkout waiting times there by a similar amount.
Which of the following, if true, most seriously weakens the director's conclusion?
ACustomers at the stores with kiosks reported greater satisfaction with checkout than did customers at the other stores.
BThe first 20 stores were chosen because their customers had expressed the strongest interest in scanning their own items; customers at the other stores strongly prefer staffed lanes.
CInstalling the kiosks cost Brightwell less than hiring enough additional cashiers to achieve the same reduction in waiting times would have cost.
DWhen the kiosks were first installed, some customers needed help from staff members to learn how to use them.
ESeveral of Brightwell's competitors have recently begun installing self-checkout kiosks in their own stores.
Show answer & explanation
Correct answer: B
Key Concept or Approach
The director assumes the remaining stores are like the first 20 in the ways that matter. Kiosks shorten waits only if customers actually use them.
Step-by-Step Solution
Step 1: Identify the task (Weaken Argument) and the gap in the reasoning: The director assumes the remaining stores are like the first 20 in the ways that matter. Kiosks shorten waits only if customers actually use them.
Step 2: (B) Correct. The first 20 stores were chosen for their customers' appetite for self-scanning. If customers at the other stores avoid kiosks, the kiosks will not relieve the staffed lanes there.
Step 3: (A) Satisfaction at the kiosk stores does not show whether waits would fall at the other stores. If anything, it slightly supports the plan.
Step 4: (C) Cost-effectiveness is irrelevant to whether waiting times will fall.
Step 5: (D) An early learning curve at the first stores did not stop the 30 percent reduction, so it gives no reason to expect a different result elsewhere.
Step 6: (E) What competitors do has no bearing on waiting times in Brightwell's stores.
Final Answer
Answer: B
Common trap: A is tempting because it reports a positive result from the kiosks, but it says nothing about whether waits will fall in the other stores; only B shows the two groups of stores differ.
Critical ReasoningStrengthen ArgumentMedium
Question 2
The Lindell Transit Authority installed screens showing real-time bus arrival times at every stop on 15 of its 60 bus routes. Over the following year, ridership on those 15 routes rose by 12 percent, compared with 3 percent on the other routes. The authority concludes that the screens attracted new riders and plans to install them at every stop in the system.
Which of the following, if true, most strengthens the authority's conclusion?
ARiders surveyed on routes with screens said they found the displayed information easy to read.
BFor several years before the screens were installed, ridership on the 15 routes had been growing faster than ridership on the other routes.
CInstalling screens throughout the system would cost less per stop than the initial installations did.
DThe 15 routes were chosen by random drawing, and during the year the authority changed neither service frequency nor fares on any of its routes.
ESome long-time riders on routes with screens reported that they now spend less time waiting at stops.
Show answer & explanation
Correct answer: D
Key Concept or Approach
The conclusion is causal: the screens caused the extra ridership. It is strengthened by ruling out other explanations for why the 15 routes grew faster.
Step-by-Step Solution
Step 1: Identify the task (Strengthen Argument) and the gap in the reasoning: The conclusion is causal: the screens caused the extra ridership. It is strengthened by ruling out other explanations for why the 15 routes grew faster.
Step 2: (D) Correct. Random selection rules out picking routes that were already growing, and unchanged frequency and fares rule out the obvious rival causes. That leaves the screens as the best explanation.
Step 3: (A) Screens that are easy to read are not evidence that they drew in new riders.
Step 4: (B) This points to an existing trend that could explain the gap, so it weakens the conclusion.
Step 5: (C) Installation cost is irrelevant to whether the screens caused the rise in ridership.
Step 6: (E) This concerns existing riders' convenience, not new riders.
Final Answer
Answer: D
Common trap: A and E describe benefits of the screens, but neither shows that the screens brought in new riders; D is the only choice that eliminates alternative causes.
Critical ReasoningResolve a ParadoxMedium
Question 3
Last year Norland Airlines cut the average fare on its routes between Kessel and Ardmore by 15 percent. Over the same year, the number of passengers Norland carried on those routes rose by 25 percent. Even so, Norland's total revenue from the Kessel-Ardmore routes was lower last year than the year before, although the airline flew the same aircraft on the routes in both years.
Which of the following, if true, most helps to explain why Norland's revenue from the routes fell?
ACompeting airlines on the Kessel-Ardmore routes also cut their fares last year.
BMost of Norland's additional passengers on the routes had previously traveled between the two cities by train.
CNorland's fuel and staffing costs on the Kessel-Ardmore routes rose last year.
DNorland added two daily departures on the Kessel-Ardmore routes last year.
EFreight carried in the cargo holds of Norland's passenger planes had supplied much of the routes' revenue, and last year the extra passengers' baggage forced Norland to carry far less freight.
Show answer & explanation
Correct answer: E
Key Concept or Approach
Fares at 85 percent with 125 percent of the passengers should raise fare revenue by about 6 percent. To explain a fall in total revenue, some other revenue on these routes must have dropped.
Step-by-Step Solution
Step 1: Identify the task (Resolve a Paradox) and the gap in the reasoning: Fares at 85 percent with 125 percent of the passengers should raise fare revenue by about 6 percent. To explain a fall in total revenue, some other revenue on these routes must have dropped.
Step 2: (E) Correct. Freight was a major source of revenue on the routes, and the extra passengers squeezed it out. The loss of freight revenue can outweigh the small gain in fare revenue.
Step 3: (A) Competitors' fares do not change how Norland's revenue follows from its own fares and passenger numbers.
Step 4: (B) Where the new passengers came from does not affect how much they paid.
Step 5: (C) Higher costs lower profit, not revenue.
Step 6: (D) More flights do not explain lower revenue from more passengers.
Final Answer
Answer: E
Common trap: C is the classic revenue-versus-profit trap: rising costs would explain lower profit, but the puzzle is about revenue.
Critical ReasoningAssumptionsMedium-hard
Question 4
Chief financial officer of Veltrix Pharmaceuticals: "Cutting the price of our Aeris asthma inhaler by 40 percent will increase our total revenue from Aeris. At the new price, Aeris will be the least expensive inhaler of its type on the market, and pharmacy data show that most patients whose insurance co-payments vary with a product's price switch to the least expensive equivalent product."
The chief financial officer's argument depends on which of the following assumptions?
AA significant proportion of patients who use inhalers of Aeris's type have insurance under which their co-payments vary with the product's price.
BVeltrix's cost of producing each Aeris inhaler will not rise as the number of inhalers it produces increases.
CMost patients who currently use Aeris are satisfied with how well it controls their asthma.
DAeris is more effective at controlling asthma than any competing inhaler of its type.
ENo competing inhaler of Aeris's type is currently sold at a price lower than Aeris's current price.
Show answer & explanation
Correct answer: A
Key Concept or Approach
The evidence covers only patients whose co-payments depend on price. For the price cut to raise revenue through switching, enough patients must fall into that group.
Step-by-Step Solution
Step 1: Identify the task (Assumptions) and the gap in the reasoning: The evidence covers only patients whose co-payments depend on price. For the price cut to raise revenue through switching, enough patients must fall into that group.
Step 2: (A) Correct. Negate it: if few patients have price-linked co-payments, few will switch, and a 40 percent price cut with little extra volume lowers revenue.
Step 3: (B) Production cost affects profit, not revenue, and the conclusion is about revenue.
Step 4: (C) The argument relies on new patients switching to Aeris, not on current users' satisfaction.
Step 5: (D) The argument relies on price, not on Aeris being the most effective inhaler.
Step 6: (E) Cheaper competitors may exist today. The claim is only that Aeris will be cheapest after the cut.
Final Answer
Answer: A
Common trap: B is tempting because it sounds like a business prerequisite, but it concerns costs and profit, while the conclusion is only about revenue.
Critical ReasoningLogical FlawMedium-hard
Question 5
A survey of 2,000 remote employees at software companies found that those who work from a dedicated home office reported, on average, 20 percent higher productivity than those who work from shared living spaces such as kitchens or living rooms. Therefore, if the software company Datavine gives each of its remote employees a stipend to set up a dedicated home office, the productivity of those employees will rise.
The reasoning in the argument is most vulnerable to criticism on the grounds that it
Arelies on a survey sample that is too small to represent remote employees at software companies
Bfails to consider that employees who have dedicated home offices may differ in other ways, such as seniority or household circumstances, that explain their higher productivity
Coverlooks the possibility that the cost of the stipends could exceed the value of any productivity gains
Dpresumes that employees who now work in shared living spaces would prefer to keep doing so
Edraws a conclusion about remote employees from evidence about employees who work in company offices
Show answer & explanation
Correct answer: B
Key Concept or Approach
The survey shows a correlation between having a dedicated office and higher productivity. The argument treats that correlation as proof that providing an office will cause higher productivity.
Step-by-Step Solution
Step 1: Identify the task (Logical Flaw) and the gap in the reasoning: The survey shows a correlation between having a dedicated office and higher productivity. The argument treats that correlation as proof that providing an office will cause higher productivity.
Step 2: (B) Correct. People who already have home offices may be more senior or have larger homes and fewer interruptions. Those factors, not the office itself, could explain the productivity gap.
Step 3: (A) A sample of 2,000 is not obviously too small, and the argument's problem lies elsewhere.
Step 4: (C) The conclusion is only that productivity will rise, not that the stipend is worthwhile, so cost is irrelevant.
Step 5: (D) The argument makes no assumption about employees' preferences.
Step 6: (E) The survey was of remote employees, so no such shift occurs.
Final Answer
Answer: B
Common trap: C is tempting because it is a sensible business objection, but the argument never claims the stipend pays for itself.
