GRE Critical Reasoning (CR) Practice Questions

Written Explanation

Mind-map: Cutting-edge building resources have been developed à new resources offer high resistance to damage à less amount of disaster-proofing material required à cost reduction in purchase of disaster-proofing materials offsets higher purchase cost of cutting-edge resources à builders using cutting-edge building resources will reduce costs (conclusion)

Missing-link: Between the cost reduction in purchase of disaster-proofing materials offsetting higher purchase cost of cutting-edge resources and the conclusion that builders using cutting-edge building resources will reduce costs

Expectation from the correct answer choice: To weaken the conclusion that builders using cutting-edge building resources will reduce costs

A. Correct. By suggesting that cutting-edge resources carry additional expenses of storage costs, this answer choice indicates that, even if the cost reduction in the purchase of disaster-proofing material offsets the higher purchase cost of the cutting-edge resources, using cutting-edge resources may not generate a reduction in total costs; so, this answer choice attacks the missing link and weakens the conclusion. Because this answer choice weakens the conclusion, this answer choice is correct.

B. If the purchase cost of disaster-proofing materials rises in the future, it indicates that builders will realize greater savings by using cutting-edge building resources; so, this answer choice strengthens, rather than weakens, the conclusion that builders using cutting-edge building resources will reduce costs. Because this answer choice does not weaken the conclusion, this answer choice is incorrect.

C. This answer choice, suggesting that high-durability versions of all construction supplies are currently not available, simply indicates that builders can use cutting-edge versions only for a limited number of building resources and realize only some cost reduction; however, “some cost reduction” still indicates that costs would be reduced; so, this answer choice, if anything, marginally strengthens, rather than weakens, the conclusion. Because this answer choice does not weaken the conclusion, this answer choice is incorrect.

D. This answer choice, suggesting that the purchase cost of cutting-edge building resources may fall in the future, indicates that, in the future, builders will realize greater savings by using cutting-edge building resources; so, this answer choice, if anything, strengthens, rather than weakens, the conclusion that builders using cutting-edge building resources will reduce costs. Because this answer choice does not weaken the conclusion, this answer choice is incorrect.

E. Trap. This answer choice, suggesting that the cutting-edge resources are not suitable for buildings demanding the greatest expenditure of disaster-proofing, indicates that the builders of such buildings may not be able to reduce their costs; however, this answer choice is limited to certain buildings and provides no information about cost reduction in buildings in general; so, this answer choice simply adds information, which, although relevant to the broad context of the argument, does not weaken the conclusion. Because this answer choice does not weaken the conclusion, this answer choice is incorrect.

A is the correct answer choice.

C is the correct answer choice.

Written Explanation

Strategy: Determining the overall conclusion of the argument and finding the relation of the highlighted portions with this conclusion

Logic: The argument presents a mathematician’s thoughts on whether Möbius and Listing independently discovered the Möbius strip. The argument mentions that the traditional belief is that the two scientists made their discoveries independently and that a finding suggests that, as the first highlighted portion states, Möbius referred to Listing’s work before Möbius made his discovery, thus drawing an intermediate conclusion that the traditional belief is false. The argument goes on to conclude that a more measured response is needed because, as the second highlighted portion states, Listing’s work referred by Möbius predates references to Möbius strip. In the context of the overall conclusion – the first highlighted portion is a fact that is used to establish an intermediate conclusion that the argument disapproves; the second highlighted portion is a fact that the argument uses to explain the disapproval of the intermediate conclusion.

Intermediate conclusion: The traditional belief is false.
Overall conclusion: A more measured response than inferring that traditional belief is false is needed.

Broad expectation from the correct answer choice:
The first highlighted portion is a fact that is used to establish an intermediate conclusion that the argument disapproves.
The second highlighted portion is a fact that the argument uses to explain the disapproval of the intermediate conclusion.

A. Incorrect. 
– The first highlighted portion is used to cast doubt on the traditional belief; however, the mathematician goes on to conclude that a more measured response is needed; so, the mathematician criticizes the position supported by the first highlighted portion; therefore, it is incorrect to state that the first highlighted portion “supports the overall position defended by the mathematician”.
– The mathematician uses the second highlighted portion to disapprove the intermediate conclusion; so, the second highlighted portion defends the mathematician’s position; therefore, it is incorrect to state that the second highlighted portion “supports a position opposite to the overall position defended by the mathematician”.

B. Incorrect.
– The first highlighted portion is used to cast doubt on the traditional belief; however, the mathematician goes on to conclude that a more measured response is needed; so, the mathematician criticizes the position supported by the first highlighted portion; therefore, it is incorrect to state that the first highlighted portion “supports the overall position defended by the mathematician”.
– The second highlighted portion supports the mathematician’s position but itself is not the position; therefore, it is incorrect to state that the second highlighted portion is the “overall position defended by the mathematician”.

C. Incorrect.
– The first highlighted portion leads to the conclusion that the traditional belief is false; so, the first highlighted portion “supports an intermediate conclusion”; however, the mathematician’s position opposes the intermediate conclusion; therefore, it is incorrect to state that the first highlighted portion “supports an intermediate conclusion drawn to provide support for the overall position defended by the mathematician”.
– The mathematician uses the second highlighted portion to disapprove the conclusion that the traditional belief is false; therefore, it is incorrect to state that the second highlighted portion goes against an intermediate conclusion “drawn to provide support for the overall position defended by the mathematician”.

D. Trap. Incorrect.
– The second highlighted portion states that Listing’s work referred by Möbius predates references to Möbius strip; the first highlighted portion states that Möbius referred to Listing’s work before making the discovery; so, the second highlighted portion does not provide additional information about the first highlighted portion; therefore, it is incorrect to state that the second highlighted portion “substantiates the first highlighted portion’s evidence that has been used in support of an intermediate conclusion criticized by the mathematician”.

E. Correct.
– The first highlighted portion is used to cast doubt on the traditional belief that the two discoveries were independent; so, the first highlighted portion supports an intermediate conclusion; however, the mathematician’s position criticizes the intermediate conclusion; therefore, it is correct to state that the first highlighted portion is “used in support of an intermediate conclusion criticized by the mathematician”.
– The mathematician uses the second highlighted portion to establish his position that a more measured response than casting doubt on the traditional belief is needed; therefore, it is correct to state that the second highlighted portion “offers support to the position held by the mathematician”.

E is the correct answer choice.

Written Explanation

Mind-map: Atlas prohibits high-level executives from joining other automobile company for five years → objection that executives cannot earn livelihood for five years (conclusion)

Missing-link: Between not joining another automobile company for five years and the conclusion that executives cannot earn livelihood for five years

Expectation from the correct answer choice: To strengthen the conclusion that executives cannot earn livelihood for five years, through a valid assumption

A. Correct. This answer choice, by suggesting that “high-level executives who leave Atlas Automobiles are capable of earning a livelihood only within the automobile industry” fills the missing link by aptly connecting “joining other automobile company” with “earning livelihood” and thereby strengthening the conclusion that high-level executives cannot earn a livelihood for five years if they don’t work at another automobile company. Additionally, this statement does have to be true for the conclusion to hold; negating this statement would mean that “high-level executives who leave Atlas Automobiles are capable of earning a livelihood even outside the automobile industry” and thus, negate the conclusion that high-level executives cannot earn a livelihood for five years if they don’t work at another automobile company. Because this answer choice strengthens the conclusion through a valid assumption, this answer choice is correct.

B. If automobile companies “typically” recruit high-level executives, it doesn’t suggest that high-level executives can only work in automobile companies; in other words, it doesn’t suggest that high-level executives are dependent on automobile companies; so, this answer choice simply adds information, which, although relevant to the broader context of the argument, does not strengthen the reasoning or its conclusion. Besides, this condition is not necessary for the argument to hold and thus, is not a valid assumption. Because this answer choice does not strengthen the conclusion through a valid assumption, this answer choice is incorrect.

C. The argument is about “high-level executives” and not concerned with “low-level executives”; so, the behavior of low-level executives after leaving Atlas Automobiles is irrelevant to the argument and its conclusion. Besides, this condition is not necessary for the argument to hold and thus, is not a valid assumption. Because this answer choice does not strengthen the conclusion through a valid assumption, this answer choice is incorrect.

D. Even if this is generally true, this statement does not support the conclusion. Additionally, “should not limit” indicates a suggesting/recommending/patronizing tone; one needs to be cautious of such answer choices as they are generally incorrect on the GRE. Besides, this condition is not necessary for the argument to hold and thus, is not a valid assumption. Because this answer choice does not strengthen the conclusion through a valid assumption, this answer choice is incorrect.

E. The restriction on the duration of a former high-level executive’s tenure at another automobile company is out of the scope of the argument and its conclusion. Besides, this condition is not necessary for the argument to hold and thus, is not a valid assumption. Because this answer choice does not strengthen the conclusion through a valid assumption, this answer choice is incorrect.

A is the best choice.

Written Explanation

Mind-map: Current COO: negotiations tactics of previous COO secured favorable agreements with vendors and labor unions → tactics antagonized local government → local government levied fines and fees → running the theme park is not profitable → previous COO: it is unfair → agreements stopped labor issues and improved efficiency → we introduced three major attractions in last two years

Missing-link: Between the current COO’s dissatisfaction about the local government levying fines that reduced the theme park’s profitability and the previous COO’s response about operational efficiency and introduction of three attractions

Expectation from the correct answer choice: Something on the lines that the previous COO ignoring the current COO’s dissatisfaction about the local government levying fines that reduced the theme park’s profitability

A. The response by the previous COO mentions that improvement in operational efficiency is a benefit caused by the favorable agreements he had secured and cites an example of the introduction of three major attractions; the response makes no suggestion about the theme park’s profits, despite the current COO expressing dissatisfaction about the local government levying fines that reduced the theme park’s profitability; so, the flaw in the previous COO’s response is the failure to respond on the issue of profitability and it is incorrect to state that the flaw is the presumption that a business will thrive if it introduces new products and services, as the answer choice mentions. Additionally, the term “furthers” indicates a previous reference to an idea in the argument; the argument has no reference to the “baseless presumption” stated in this answer choice, invalidating this answer choice. Because this answer choice does not indicate the flaw in the previous COO’s response, this answer choice is incorrect.

B. The response by the previous COO mentions that improvement in operational efficiency is a benefit caused by the favorable agreements he had secured and cites an example of the introduction of three major attractions; the response cites evidence about the introduction of attractions that support an alternate conclusion that the previous COO’s negotiations tactics were beneficial; however, the response fails to address the current COO’s dissatisfaction about the local government levying fines that reduced the theme park’s profitability, making the response incomplete and thus, flawed; overall, it is incorrect to state that refuting the criticism without citing evidence that supports an alternate conclusion is the flaw in the previous COO’s response, as the answer choice mentions. Because this answer choice does not indicate the flaw in the previous COO’s response, this answer choice is incorrect.

C. The response by the previous COO mentions that improvement in operational efficiency is a benefit caused by the favorable agreements he had secured and cites an example of the introduction of three major attractions; although the response does not suggest a definite causal relationship between improved operating efficiency and the introduction of new attractions, the failure to suggest such a relationship is not the flaw in the previous COO’s response; the flaw in the response is that it fails to address the current COO’s dissatisfaction about the local government levying fines that reduced the theme park’s profitability, thus making the response incomplete. Because this answer choice does not indicate the flaw in the previous COO’s response, this answer choice is incorrect.

D. The response by the previous COO mentions that improvement in operational efficiency is a benefit caused by the favorable agreements he had secured and cites an example of the introduction of three major attractions; the response makes no suggestion about the theme park’s profits, despite the current COO expressing dissatisfaction about the local government levying fines that reduced the theme park’s profitability; so, it is incorrect to state that the flaw is the assumption that the new major attractions will increase profits, as the answer choice mentions; the flaw in the response is that it fails to address the current COO’s dissatisfaction about the local government levying fines that reduced the theme park’s profitability, thus making the response incomplete. Because this answer choice does not indicate the flaw in the previous COO’s response, this answer choice is incorrect.

E. Correct. The current COO raises two points – acknowledgment of favorable agreements with vendors and labor unions and dissatisfaction about the local government levying fines that reduced the theme park’s profitability; the response by the previous COO mentions that improvement in operational efficiency is a benefit because of favorable agreements and cites an example of the introduction of three major attractions; the previous COO’s response fails to address the current COO’s dissatisfaction about the local government levying fines that reduced the theme park’s profitability, thus making the response incomplete and thus, flawed. Because this answer choice indicates the flaw in the previous COO’s response, this answer choice is correct.

E is the best choice.

Written Explanation

Mind-map: Instrument tracks a pod of twenty-three dolphins → measures sonar pulses released by the dolphins for forty miles → for one mile, one more pattern of sonar pulses was tracked → even if the additional pattern was produced by a twenty-fourth dolphin → the twenty-fourth dolphin could be travelling all forty miles because _____

Missing-link: Between additional pattern by the twenty-fourth dolphin being tracked only for one mile and the possibility of twenty-fourth dolphin travelling all forty miles

Expectation from the correct answer choice: Something on the lines of an explanation for why the pattern by the twenty-fourth dolphin was tracked only for one mile if the dolphin could have travelled all forty miles

A. Correct. By suggesting that the twenty-fourth dolphin could have released a sonar pattern only for one mile and remained silent elsewhere, this answer choice indicates a possibility in which, owing to the dolphin releasing sonar pulses only for one mile, the twenty-fourth pattern was tracked only for a mile even if the twenty-fourth dolphin could have travelled for all forty miles. Because this answer choice effectively completes the chain of thoughts developed in the passage, this answer choice is correct.

B. The argument is concerned with the explanation for the pattern by the twenty-fourth dolphin and not with the patterns by other animals; so, this answer choice is out of scope and fails to effectively complete the chain of thoughts developed in the passage. Because this answer choice does not duly complete the passage, this answer choice is incorrect.

C. Trap. This answer choice, suggesting that the distance between two dolphins in a pod may be changing through their journey, makes no suggestion regarding the pattern by the twenty-fourth dolphin, thus failing to explain why the twenty-fourth pattern was tracked only for a mile if the twenty-fourth dolphin could have travelled for all forty miles. Because this answer choice does not effectively complete the chain of thoughts developed in the passage, this answer choice is incorrect.

D. This answer choice, suggesting that the twenty-fourth pattern was not the strongest, makes no suggestion regarding why the pattern was tracked only for a mile if the dolphin could have travelled for all forty miles, thus failing to effectively complete the chain of thoughts developed in the passage. Because this answer choice does not duly complete the passage, this answer choice is incorrect.

E. The argument is concerned with the explanation for the sonar pattern by the twenty-fourth dolphin; so, this answer choice, suggesting that fewer dolphins would have been observed if sonar pulses were not used to track the dolphins, is just additional information and fails to effectively complete the chain of thoughts developed in the passage. Because this answer choice does not duly complete the passage, this answer choice is incorrect.

A is the best choice.

E is the correct answer choice.

Written Explanation

Mind-map: Bit Byte sells copper wire connections for low fee and fiber optic connections for higher fee → to Bit Byte, fiber optic connections cost less per unit of data usage than copper wire connections → providing fiber optic connections to all customers at current low-fee rate will decrease profits

Missing-link: Between fiber optic connections costing less per unit of data usage than copper wire connections and providing fiber optic connections to all customers at current low-fee rate decreasing profits

Expectation from the correct answer choice: To explain why providing fiber optic connections to all customers at current low-fee rate will decrease profits despite fiber optic connections costing less per unit of data usage than copper wire connections

A. The argument is concerned with the effect on “Bit Byte’s profit” if all its connections are moved to fiber optics; so, the “company’s competitors’ plans” are out of scope. Because this answer choice does not explain the discrepancy in the argument, this answer choice is incorrect.

B. The argument mentions that fiber optics connections are offered at a higher fee than copper wire connections “now” and is concerned with the effect on profit if all connections are moved to fiber optics; so, information about the “past” increase in the fee of the two types of connections has already been accounted for and has no bearing on the argument. Because this answer choice does not explain the discrepancy in the argument, this answer choice is incorrect.

C. Trap. This answer choice, suggesting that only a small proportion of all customers pay a higher fee for fiber optics connection, indicates that, if all connections are moved to fiber optics at a low fee, the revenue lost will likely be small but does not explain why the move will decrease profits. Because this answer choice does not explain the discrepancy in the argument, this answer choice is incorrect.

D. Correct. By suggesting that the difference in the revenue of fiber optics connection and copper wire connections is higher than the difference in the costs of providing copper wire connections and fiber optics connections, this answer choice indicates that, if all connections are moved to fiber optics at a low fee, the revenue lost will be higher than the costs saved, thus explaining why the move will decrease profits. Because this answer choice clarifies the exact discrepancy, this answer choice is correct.

E. Trap. The argument is concerned with the effect on profit if all connections are moved to fiber optics “now”; so, information about the impact on profits at the “time of the initial offering of fiber optics connections” has already been accounted for and does not explain the discrepancy in the argument. Because this answer choice does not explain the discrepancy in the argument, this answer choice is incorrect.

D is the correct answer choice.

E is the correct answer choice.

Written Explanation

Mind-map: Conservationist: my critics cite increase in amount of oil extracted as no risk of oil exhaustion → specious argument similar to saying that faster groundwater depletion demonstrates no danger of water depletion → real reason of increase in amount of oil extracted is improvement in extraction technology

Missing-link: Not needed

Expectation from the correct answer choice: Something on the lines of there is risk of oil exhaustion

A. Trap. The argument mentions that the conservationist’s critics argue that there is no risk of oil exhaustion because more oil is getting extracted; the argument also mentions that the conservationist believes that oil is getting depleted and that the depletion is because of improved oil extraction technology; however, the argument makes no suggestion regarding the general cause-effect relationship between the use of technology and depletion of natural resources; so, this answer choice cannot be established. Because this answer choice does not indicate a conclusion of the argument, this answer choice is incorrect.

B. The argument makes no mention of the quantity of oil in a country or any means to measure it; so, this answer choice cannot be established. Because this answer choice does not indicate a conclusion of the argument, this answer choice is incorrect.

C. The argument makes no mention of arable land or any entity that correlates with the proportion of oil extracted; so, this answer choice is out of scope. Because this answer choice does not indicate a conclusion of the argument, this answer choice is incorrect.

D. Correct. The argument mentions that the conservationist’s critics argue that there is no risk of oil exhaustion because more oil is getting extracted and that the conservationist regards the critics’ argument as “specious” and “unsound”, suggesting that the conservationist believes that the danger of oil depletion exists, as the answer choice mentions. Because this answer choice indicates a conclusion of the argument, this answer choice is correct.

E. The argument mentions that the conservationist believes that oil is getting depleted and that the depletion is because of improved oil extraction technology; however, the argument makes no mention of wastage of resources or of low-quality oil; so, this answer choice cannot be established. Because this answer choice does not indicate a conclusion of the argument, this answer choice is incorrect.

D is the best choice.