Examkin

Identifying Unstated Assumptions

34 questions

All types34Multiple choice17True / False17
Question 1Question →

In an effort to lower operating costs, the municipal transit authority of Oakhaven plans to replace its entire fleet of diesel-powered buses with electric buses. Management projects that this transition will significantly decrease total annual maintenance costs for the transit system, because electric buses have fewer moving mechanical parts than diesel buses do.

Which of the following is an assumption on which the municipal transit authority's projection depends?

Show answer & explanation

Answer: The ongoing maintenance costs for the electronic and battery components of electric buses will not exceed the savings achieved from having fewer mechanical parts.

Answer

The ongoing maintenance costs for the electronic and battery components of electric buses will not exceed the savings achieved from having fewer mechanical parts.
The argument concludes that total annual maintenance costs will decrease because electric buses have fewer moving mechanical parts. For this to hold true, any new or existing maintenance costs associated with non-mechanical systems (such as batteries, software, and electrical wiring) must not outweigh the savings realized from reduced mechanical maintenance. If non-mechanical maintenance expenses exceed those mechanical savings, the overall maintenance budget will not decrease.

Step-by-Step Solution

1
Deconstruct the argument into premise and conclusion.
Premise: Electric buses have fewer moving mechanical parts than diesel buses. Conclusion: Replacing the fleet with electric buses will significantly decrease total annual maintenance costs.
Isolating the premise and conclusion reveals the scope gap between mechanical parts and total maintenance costs.
2
Identify the underlying logical gap.
The author assumes that savings gained from having fewer mechanical parts will not be offset or surpassed by new non-mechanical maintenance expenses specific to electric buses.
Total maintenance costs encompass all components of a vehicle, not just mechanical ones.
3
Apply the Negation Test to verify the assumption.
Logical Negation: Non-mechanical maintenance costs WILL exceed the savings achieved from having fewer mechanical parts. Outcome: If this negated statement is true, total maintenance costs will increase or stay the same, completely destroying the conclusion.
A valid assumption must be necessary for the conclusion to hold true.

Key Concept

Identifying Unstated Assumptions
Question 2Question →

A corporate logistics firm plans to reduce carbon emissions by replacing its fleet of diesel trucks with electric vehicles. Management argues that because the local electricity grid is powered primarily by zero-emission hydroelectric dams, this fleet transition will eliminate the company's net greenhouse gas emissions from freight transportation. Evaluate whether the following claim is a necessary unstated assumption of the management's argument: The total lifecycle emissions generated during the manufacturing and disposal of the electric vehicle fleet will not exceed the operational emissions produced by the existing diesel fleet over the same period.

Show answer & explanation

Answer: True

Answer

True. The claim represents a necessary unstated assumption required for the argument's conclusion to hold.
The author concludes that replacing diesel trucks with electric vehicles will eliminate net greenhouse gas emissions from freight transportation, relying solely on the premise that the electricity used during operation comes from zero-emission hydroelectric dams. For the total net emissions to be eliminated, non-operational sources of emissions associated with the new fleet—specifically manufacturing and disposal—must not outweigh the operational emissions saved by abandoning diesel. Negating the statement establishes that manufacturing and disposal emissions would exceed diesel operational emissions, which directly contradicts the claim that net emissions will be eliminated. Therefore, the argument depends on this unstated assumption.

Step-by-Step Solution

1
Deconstruct the argument into premise and conclusion.
Premise: The electricity grid powering the new electric vehicles relies on zero-emission hydroelectric energy. Conclusion: Replacing diesel trucks with electric vehicles will eliminate net greenhouse gas emissions from freight transportation.
Isolating the core argument components allows identification of structural gaps between the premise and conclusion.
2
Apply the Negation Test to the proposed assumption.
Negated claim: The total lifecycle emissions generated during manufacturing and disposal of the electric vehicle fleet WILL exceed the operational emissions of the diesel fleet over the same period.
If the logically negated form of a statement logically destroys the conclusion, that statement is a necessary assumption.
3
Evaluate the impact of the negated statement on the author's conclusion.
If producing and disposing of electric vehicles creates more emissions than operating diesel trucks saves, net emissions from freight transportation will increase rather than reach zero.
The claim of total net emission elimination fails entirely if unmeasured non-operational stages produce a net surge in emissions.

Key Concept

Identifying Unstated Assumptions via the Negation Test
Question 3Question →

To combat declining wild bee populations, environmental officials in Region X plan to restrict the agricultural use of neonicotinoid pesticides, citing a study showing that bee colonies in uncultivated nature reserves suffer far lower mortality rates than those near commercial farmland. The officials conclude that enforcing this restriction across all farms in Region X will restore local wild bee populations to healthy levels.

Which of the following is an assumption on which the environmental officials' argument depends?

Show answer & explanation

Answer: The lower mortality rate of bee colonies in nature reserves is not primarily attributable to environmental differences other than the absence of neonicotinoid pesticides.

Answer

The argument assumes that the lower mortality rate of bee colonies in nature reserves is not primarily attributable to environmental differences other than the absence of neonicotinoid pesticides.
The conclusion relies on a causal link between neonicotinoid exposure and high bee mortality. For the proposed restriction to restore bee populations, the observed survival advantage in nature reserves must actually stem from the absence of neonicotinoids rather than other confounding factors (such as superior forage or fewer parasites). Negating this choice reveals that if other factors are the primary cause, the plan will fail, proving it is a necessary unstated assumption.

Step-by-Step Solution

1
Deconstruct the argument structure
Premise: Bee colonies in nature reserves (where neonicotinoids are absent) have lower mortality than those near commercial farmland. Conclusion: Restricting neonicotinoids on farmland will restore wild bee populations.
Identifying the gap between the observed correlation (reserves vs. farmland) and the proposed causal intervention (restricting neonicotinoids) is essential.
2
Identify the logical gap
The author assumes that the absence of neonicotinoids is the primary cause of lower bee mortality in reserves, ruling out alternative confounding variables.
If other differences between reserves and farmland cause the mortality gap, removing neonicotinoids will fail to achieve the intended result.
3
Apply the Negation Test to verify the correct assumption
Negated claim: 'The lower mortality rate in nature reserves IS primarily attributable to environmental differences other than the absence of neonicotinoids.' If true, restricting neonicotinoids will not restore bee populations, completely invalidating the conclusion.
A statement is a required assumption if and only if its logical negation shatters the conclusion of the argument.

Key Concept

Identifying Unstated Assumptions via the Negation Test
Estimated Time:2m 0s
Question 4Question →

Consider the following argument:

A regional agricultural authority plans to mitigate groundwater depletion by offering financial subsidies to farmers who replace water-intensive flood irrigation systems with high-efficiency drip irrigation. The authority argues that because drip irrigation reduces per-acre water consumption by 30 percent, implementing this subsidy program will lead to a net reduction in total agricultural groundwater extraction across the region.

Statement: The agricultural authority's argument relies on the unstated assumption that farmers receiving the subsidies will not expand their total irrigated acreage using the water volume saved through drip irrigation.

Show answer & explanation

Answer: True

Answer

The statement is True. The argument relies on the unstated assumption that farmers receiving subsidies will not expand their total irrigated acreage using the conserved water.
The statement accurately identifies a necessary unstated assumption. The author leaps from a per-acre efficiency gain (a 30% reduction per acre) to a regional aggregate reduction (net decrease in total groundwater extraction). For this claim to hold, total irrigated acreage must not expand to absorb the conserved water. Applying the Negation Test shows that if farmers do expand their acreage using the saved water, the conclusion collapses.

Step-by-Step Solution

1
Deconstruct the core argument into premises and conclusion
Premise: Drip irrigation reduces per-acre water consumption by 30 percent.
Premise: Subsidies will incentivize farmers to switch from flood to drip irrigation.
Conclusion: The subsidy program will lead to a net reduction in total agricultural groundwater extraction across the region.
Identifying the explicit claims reveals the structural gap between per-acre efficiency and total regional consumption.
2
Identify the logical gap between the premise and the conclusion
The premise concerns rate/efficiency (water consumption per acre), whereas the conclusion asserts an outcome regarding total volume (total regional extraction).
Total volume extracted is a function of both rate per acre and total acreage irrigated (Total=Rate×AcresTotal = Rate \times Acres).
3
Apply the Negation Test to evaluate the assumption
Negated statement: Farmers receiving subsidies WILL expand their total irrigated acreage using the saved water volume.
Impact: If farmers increase their irrigated acreage using the 30% saved water, aggregate regional groundwater extraction will not drop, invalidating the conclusion.
A statement is a necessary unstated assumption if its logical negation invalidates the argument's conclusion.

Key Concept

Identifying Unstated Assumptions (Per-Unit Efficiency vs. Total Aggregate Volume Gap)
Question 5Question →

A major software enterprise recently introduced a specialized cybersecurity training program for its third-party software vendors. The company's executive board claims that because vendors who voluntarily completed the training during its pilot phase experienced a 40 percent drop in data breach incidents compared to their pre-training levels, mandating the training for all remaining vendors will significantly reduce the enterprise's overall exposure to third-party data breaches.

Which of the following is an assumption on which the executive board's claim depends?

Show answer & explanation

Answer: The vendors who voluntarily completed the training during the pilot phase were not inherently better equipped to implement security improvements than the remaining vendors.

Answer

The argument depends on assuming that the vendors who voluntarily participated in the pilot program were not fundamentally better suited to benefit from the training than the non-pilot vendors.
The conclusion relies on generalizing the success of a voluntary pilot program to all remaining vendors. For this generalization to hold, the pilot participants must be representative of the whole population in their ability to translate the training into breach reductions. The correct choice addresses this self-selection gap: if the pilot vendors were inherently more capable of improving security, the remaining vendors would not achieve similar results, invalidating the executive board's expectation.

Step-by-Step Solution

1
Deconstruct the argument structure
Premise: Vendors who voluntarily took pilot training saw a 40% breach reduction. Conclusion: Mandating training for all remaining vendors will significantly reduce overall third-party breach exposure.
Identifying the jump from a voluntary pilot sample to a mandatory universal rule highlights potential sampling and self-selection gaps.
2
Formulate the required assumption (gap identification)
The author assumes that the success observed in the voluntary pilot group will replicate across the remaining non-pilot group.
If the pilot group possessed unique baseline advantages, the remaining vendors will not achieve similar improvements upon mandate.
3
Apply the Negation Test to the candidate assumption
Negated statement: The voluntary pilot vendors WERE inherently better equipped to implement security improvements than the remaining vendors.
If the remaining vendors lack the capacity to implement these improvements, mandating the course will fail to significantly reduce overall breach exposure, completely shattering the conclusion.

Key Concept

Identifying Unstated Assumptions (Selection Bias & Sample Representativeness)
Question 6Question →

Consider the following argument: A pharmaceutical research institute evaluated a novel antihypertensive drug by administering it to a cohort of patients over twelve weeks. The study recorded a statistically significant reduction in blood pressure in patients receiving the new drug compared to those receiving the standard treatment. Based on these findings, the lead researcher concluded that adopting the new drug in standard clinical practice will decrease the overall rate of major cardiovascular events among hypertensive patients. Evaluate whether the following claim represents an unstated assumption necessary to the researcher's argument:

'The researcher's conclusion relies on the unstated assumption that a statistically significant short-term reduction in blood pressure translates into a long-term reduction in overall major cardiovascular events.'

Show answer & explanation

Answer: True

Answer

The statement is True. The argument requires the unstated assumption that short-term blood pressure lowering correlates with long-term reductions in major cardiovascular events.
The evaluated statement correctly identifies a necessary assumption. The argument connects a short-term surrogate marker (twelve-week blood pressure drop) to a broader clinical outcome (reduction in major cardiovascular events). By negating the statement—positing that short-term blood pressure drops do not lead to fewer long-term cardiovascular events—the conclusion loses all logical support. Therefore, the assumption is necessary.

Step-by-Step Solution

1
Deconstruct the argument structure into premise and conclusion.
Premise: Patients taking the new drug experienced statistically significant blood pressure reductions over a 12-week trial compared to standard treatment. Conclusion: Replacing the standard treatment with the new drug will reduce overall rates of major cardiovascular events.
Identifying the gap between the evidence provided (12-week surrogate marker) and the final claim (long-term clinical outcome) is essential for locating unstated assumptions.
2
Identify the logical leap between premise and conclusion.
The argument assumes that achieving a short-term reduction in a biological metric (blood pressure) necessarily leads to a reduction in long-term health outcomes (major cardiovascular events).
An unstated assumption must bridge the gap between what is known from the premise and what is claimed in the conclusion.
3
Apply the Negation Test to the statement.
Negated statement: Short-term blood pressure reductions do NOT translate into long-term reductions in major cardiovascular events. If this negated claim is true, the 12-week study results provide no basis for concluding that major cardiovascular events will decrease.
If the negated assumption destroys the validity of the argument, the original assumption is strictly necessary.

Key Concept

Negation Test for Unstated Necessary Assumptions
Question 7Question →

To combat fraudulent crop loss claims, a national agricultural insurer plans to require all policyholders to submit high-resolution satellite imagery of their farmland taken immediately before and after any reported severe weather event. The insurer reasons that comparing these images will enable claims adjusters to verify whether physical crop damage actually occurred as a direct result of the weather event, thereby eliminating payouts for pre-existing crop degradation or unverified losses.

Which of the following is an assumption on which the insurer's plan depends?

Show answer & explanation

Answer: High-resolution satellite imagery can provide enough detail to distinguish pre-existing crop degradation from physical damage caused by a severe weather event.

Answer

The insurer's plan relies on the assumption that high-resolution satellite imagery can provide enough detail to distinguish pre-existing crop degradation from physical damage caused by a severe weather event.
The conclusion asserts that comparing satellite images will eliminate payouts for pre-existing crop degradation by verifying whether damage resulted directly from a weather event. For this verification process to work, the satellite images must possess sufficient resolution and detail to differentiate between crop degradation present before the storm and new damage caused by the storm. If the images cannot distinguish between these two states, adjusters cannot verify causality, and the plan fails. Therefore, this statement is a necessary unstated assumption.

Step-by-Step Solution

1
Deconstruct the argument into premises and main conclusion.
Premise: Insurers will require satellite imagery immediately before and after severe weather. Premise: Adjusters will compare images to verify if damage was directly caused by the storm. Conclusion: The plan will eliminate payouts for pre-existing degradation or unverified losses.
Identifying the logic gap requires clearly isolating what the premises establish versus what the conclusion claims.
2
Identify the unstated logical gap between the premise and conclusion.
The premises state that images will be compared, but assume that comparing these images actually enables adjusters to tell pre-existing damage apart from new weather damage.
An assumption is an unstated premise required to bridge the gap between the evidence provided and the outcome claimed.
3
Apply the Negation Test to confirm logical necessity.
Negated statement: 'High-resolution satellite imagery CANNOT provide enough detail to distinguish pre-existing degradation from weather damage.' If true, comparing images fails to verify causality, shattering the conclusion that fraudulent payouts will be eliminated.
If the negated version of a choice causes the argument to collapse, that choice is a strictly necessary assumption.

Key Concept

Identifying Unstated Assumptions using the Negation Test
Estimated Time:1m 50s
Question 8Question →

To reduce the severity of summer wildfires, a municipal forestry board plans to replace mechanical brush-clearing with controlled goat grazing along park perimeters. Mechanical clearing leaves behind dry, shredded plant residue that remains combustible on the forest floor for several months. In contrast, goats consume underbrush completely, eliminating ground residue. The board concludes that substituting goat grazing for mechanical clearing will significantly decrease the overall intensity of wildfires in these perimeters during the dry season.

Which of the following is an assumption on which the forestry board's argument depends?

Show answer & explanation

Answer: The goats used for controlled grazing will not preferentially avoid the most flammable shrub species in favor of fire-resistant vegetation.

Answer

The argument assumes that the goats will not selectively avoid consuming the specific shrub species that contribute most to fire intensity.
The conclusion asserts that replacing mechanical clearing with goat grazing will decrease wildfire intensity because goats consume underbrush without leaving flammable ground residue. For this plan to succeed, the goats must actually eat the vegetation that creates the high fire risk. If the goats preferentially avoid the most flammable plants, those hazardous fuels will remain in the forest perimeter, rendering goat grazing ineffective at reducing fire intensity. Therefore, the argument depends on the assumption that goats will not selectively bypass the most flammable plants.

Step-by-Step Solution

1
Deconstruct the argument structure
Premise 1: Mechanical clearing leaves combustible shredded residue. Premise 2: Goats consume underbrush completely without leaving ground residue. Conclusion: Goat grazing will significantly decrease overall wildfire intensity compared to mechanical clearing.
Identifying premises and conclusion exposes the logical leap between total plant consumption and effective fire mitigation.
2
Identify the logical gap
The author assumes that goat grazing effectively removes the key combustible vegetation without introducing new vulnerabilities (such as leaving highly flammable plant species untouched).
The conclusion relies on the physical reduction of wildfire fuel.
3
Apply the Negation Test to the correct option
Negated statement: Goats WILL preferentially avoid the most flammable shrub species and consume fire-resistant vegetation instead. If true, the primary fire hazards remain standing, which destroys the conclusion that fire intensity will decrease.
A valid unstated assumption must be essential; its negation shatters the author's reasoning.

Key Concept

Identifying Unstated Assumptions via the Negation Test
Question 9Question →

A commercial vertical farm located in a high-latitude urban center plans to reduce its energy overhead by replacing half of its indoor electric LED grow lights with a passive fiber-optic system that collects natural sunlight via rooftop lenses and pipes it into cultivate chambers. Management contends that because electricity consumed by artificial lighting accounts for over sixty percent of the farm's monthly operating expenditures, implementing this solar piping system will significantly decrease total monthly operating expenses. Which of the following is an assumption on which management's argument depends?

Show answer & explanation

Answer: The maintenance and operating costs associated with the rooftop tracking lenses will not equal or exceed the monetary savings generated from lower electricity usage.

Answer

The argument depends on the assumption that the costs required to operate and maintain the new rooftop collection system will not outweigh or negate the financial savings achieved from reduced electricity consumption.
Management concludes that total monthly operating expenses will fall because electricity usage drops. For a reduction in one specific expense (electricity) to lead to a net reduction in total operating expenses, the replacement technology must not incur new secondary operating expenses (such as maintenance for rooftop collectors) that equal or outweigh the savings. Applying the Negation Test confirms this: if maintenance costs do meet or exceed electricity savings, total monthly operating expenses will not decrease.

Step-by-Step Solution

1
Analyze the argument structure
Premise: LED lighting accounts for over 60% of monthly operating expenses. Premise: Replacing half the LEDs with a passive fiber-optic sunlight system reduces electricity usage. Conclusion: Implementing the system will significantly decrease overall monthly operating expenses.
Deconstructing the argument isolates the leap from electricity savings to total operational expense reduction.
2
Identify potential logical gaps
The argument assumes that saving money on electricity will translate into overall operational savings without introducing new costs that negate those savings.
An unstated necessary assumption must bridge the gap between electricity savings and total cost reduction.
3
Apply the Negation Test to candidate statements
Negating the statement regarding system maintenance yields: 'The maintenance and operating costs of the rooftop tracking lenses WILL equal or exceed the monetary savings generated from lower electricity usage.'
If the negated version shatters the conclusion, the original statement is a strictly necessary assumption.
4
Evaluate the impact of the negated statement on the conclusion
If maintenance expenses equal or exceed the electricity savings, total monthly operating expenses will not fall. The argument collapses.
This confirms that the option concerning maintenance costs is a required unstated assumption.

Key Concept

Identifying Unstated Assumptions
Question 10Question →

A municipal transit authority plans to replace station ticket window personnel with automated self-service kiosks in order to reduce station operating expenses. The authority claims that because automated kiosks eliminate the need to pay hourly wages to human ticket agents, implementing this system will successfully decrease the total monthly operational costs of running the transit stations. Which of the following is an assumption on which the transit authority's argument depends?

Show answer & explanation

Answer: The ongoing maintenance and operational costs of the automated kiosks will not equal or exceed the payroll savings gained from removing ticket window personnel.

Answer

The argument assumes that the ongoing maintenance and operational costs of the automated kiosks will not equal or exceed the payroll savings gained from removing ticket window personnel.
The conclusion asserts that replacing human ticket agents with automated kiosks will lower overall station operating expenses. This relies on the implicit premise that the new expense (kiosk maintenance and operation) will be smaller than the eliminated expense (agent wages). Negating this option—assuming kiosk maintenance costs equal or exceed wage savings—shatters the conclusion that overall costs will fall.

Step-by-Step Solution

1
Identify the conclusion and premise
Premise: Automated kiosks eliminate wage expenses for ticket agents. Conclusion: Implementing kiosks will reduce overall station operating expenses.
Understanding the logical jump between removing wage expenses and achieving total cost reduction reveals the necessary assumption.
2
Apply the Negation Test to the candidate assumption
Negating the statement gives: 'The maintenance and operational costs of kiosks WILL equal or exceed the saved payroll expenses.'
If negated costs match or outweigh savings, overall station operating expenses will not drop, causing the argument to fail.

Key Concept

Identifying Unstated Assumptions (Negation Test)
Question 11Question →

Consider the following argument: A regional art museum recently replaced all single-use plastic water bottles in its cafeteria with reusable glass bottles. Museum administrators claim that this policy will significantly reduce the cafeteria's overall carbon footprint over the coming year. Evaluate the following statement: The argument depends on the assumption that the energy consumed in manufacturing and repeatedly washing the reusable glass bottles does not produce greenhouse gas emissions that equal or exceed the emissions saved by eliminating the single-use plastic bottles.

Show answer & explanation

Answer: True

Answer

True
The statement accurately expresses a necessary unstated assumption of the argument. If the emissions involved in creating and repeatedly cleaning the glass bottles were equal to or higher than those generated by single-use plastic bottles, switching to glass would fail to reduce the carbon footprint, undermining the administrators' claim.

Step-by-Step Solution

1
Deconstruct the argument into its core premise and conclusion.
Premise: The museum replaced single-use plastic bottles with reusable glass bottles. Conclusion: The policy will significantly lower the cafeteria's carbon footprint.
Identifying the gap between the premise and conclusion reveals what must be assumed for the conclusion to be valid.
2
Apply the Negation Test to the statement.
Negated Statement: The energy consumed in producing and washing glass bottles DOES produce emissions equal to or greater than the emissions saved from eliminating plastic bottles.
If the logical negation of a statement invalidates the argument's conclusion, that statement is a necessary unstated assumption.
3
Evaluate the impact of the negated statement on the conclusion.
If glass bottle lifecycle emissions equal or exceed plastic bottle emissions, the conclusion that the carbon footprint will decrease is destroyed.
Because negating the statement breaks the argument, the statement is a required unstated assumption.

Key Concept

Identifying Unstated Assumptions via the Negation Test
Question 12Question →

An international airline recently decided to replace heavy printed inflight magazines with digital versions accessible via passengers' personal mobile devices. Management claims that removing the printed magazines will significantly reduce the aircraft's weight and overall fuel consumption during flights. Therefore, management concludes that the airline's total operating expenses will decrease starting next month. Which of the following is an assumption on which the management's conclusion depends?

Show answer & explanation

Answer: The operational costs required to provide and maintain the digital magazine platform will be less than the monetary savings achieved from reduced fuel consumption.

Answer

The operational costs required to provide and maintain the digital magazine platform will be less than the monetary savings achieved from reduced fuel consumption.
The conclusion asserts that total operating expenses will decline because fuel consumption drops. For a net decrease in total expenses to occur, the new expenses created by switching to digital magazines must not exceed the savings in fuel costs. If digital platform maintenance costs more than the saved fuel money, total operating expenses would actually rise or stay equal, completely undermining the conclusion.

Step-by-Step Solution

1
Identify the premises and conclusion of the argument.
Premises: Removing printed magazines reduces weight and fuel consumption. Conclusion: Total operating expenses will decrease starting next month.
Understanding the logical bridge between fuel savings and net expense reduction is essential to identifying the logical gap.
2
Identify the unstated logical gap.
The argument assumes that saving money on fuel will not be offset by new costs associated with the digital alternative.
Lowering one expense line item does not guarantee lower total expenses if a new expense is higher than the savings.
3
Apply the Negation Test to verify the assumption.
If digital platform costs are equal to or greater than fuel savings, total operating expenses will not decrease, causing the conclusion to fall apart.
A necessary assumption must shatter the conclusion when logically negated.

Key Concept

Identifying Unstated Assumptions via Negation Test
Question 13Question →

Consider the following argument: A regional courier company plans to replace its gasoline-powered delivery vans with electric vehicles in order to lower its annual fuel expenditures. The company's director claims that making this fleet replacement will increase the company's net annual profit.

True or False: The director's argument depends on the unstated assumption that the cost savings from lower fuel expenditures will not be exceeded by the costs of acquiring and maintaining the electric vehicles.

Show answer & explanation

Answer: True

Answer

True. The argument assumes that the reduction in fuel expenses will not be negated or outweighed by the new expenses associated with electric vehicles.
The conclusion asserts a net financial gain based on reducing a single cost category (fuel). For net profit to increase, total financial benefits must outweigh total costs. If the secondary costs of electric vehicle adoption outweigh the fuel savings, the conclusion breaks down. Hence, assuming those secondary costs will not exceed fuel savings is logically necessary.

Step-by-Step Solution

1
Identify the premise and conclusion of the argument.
Premise: Replacing gasoline vans with electric vehicles lowers annual fuel expenditures. Conclusion: The fleet replacement will increase net annual profit.
Understanding the logical jump between premise and conclusion highlights the underlying assumption.
2
Apply the Negation Test to the evaluated claim.
Negated statement: The cost savings from lower fuel expenditures WILL be exceeded by the costs of acquiring and maintaining the electric vehicles.
Logical negation tests whether an assumption is strictly required for the conclusion to stand.
3
Evaluate the impact of the negated statement on the conclusion.
If additional vehicle costs exceed fuel savings, net annual profit will decrease instead of increasing. The conclusion collapses.
Because the negated statement destroys the argument's conclusion, the original statement is a necessary unstated assumption.

Key Concept

Identifying Unstated Assumptions (Negation Test)
Question 14Question →

The municipal electric utility of a small district recently announced a plan to replace its natural gas electricity supply with solar power. The utility directors argue that because generating electricity from solar power currently costs significantly less per megawatt-hour than generating it from natural gas, adopting solar power will reduce the total monthly electricity bills of local residents. Which of the following is an assumption on which the utility directors' argument depends?

Show answer & explanation

Answer: The additional expenses required to transmit and integrate solar energy into the local power grid will not exceed the savings gained from lower generation costs.

Answer

The argument depends on the assumption that additional expenses to transmit and integrate solar energy into the local power grid will not exceed the savings gained from lower generation costs.
The argument moves from a premise about lower generation costs to a conclusion about lower overall monthly bills. For this conclusion to hold, other non-generation expenses associated with adopting solar power—such as grid transmission and integration—must not exceed the money saved on generation. Negating this statement directly invalidates the author's conclusion.

Step-by-Step Solution

1
Identify the premises and conclusion of the argument.
Premise: Generating solar power costs less per megawatt-hour than natural gas. Conclusion: Switching to solar power will reduce total monthly electricity bills.
Understanding the logical jump between lower generation cost and lower overall bills is essential for identifying unstated assumptions.
2
Identify potential gaps between the premise and conclusion.
The argument assumes generation cost is the only relevant factor determining final electricity bills.
If secondary costs (such as grid integration or transmission) outweigh generation savings, total costs will increase.
3
Apply the Negation Test to the correct choice.
Negating the option gives: 'Additional transmission and integration costs WILL exceed the savings.' This completely shatters the conclusion that overall bills will be reduced.
A valid assumption must collapse the conclusion when logically negated.

Key Concept

Identifying Unstated Assumptions using the Negation Test
Estimated Time:1m 0s
Question 15Question →

A specialty pharmaceutical company plans to transition the synthesis of its primary active ingredient from traditional batch processing to continuous flow manufacturing. Management claims that this operational shift will lower the overall production cost per unit by at least 20 percent. This claim is grounded in the observation that continuous flow processing completely eliminates the multi-day downtime currently required between batches for vessel sterilisation and quality re-validation.

Which of the following is an assumption on which the management's argument depends?

Show answer & explanation

Answer: The expenses involved in maintaining continuous flow equipment will not equal or exceed the cost savings gained from eliminating vessel sterilisation and re-validation downtime.

Answer

The argument relies on the assumption that the expenses involved in maintaining continuous flow equipment will not equal or exceed the cost savings gained from eliminating sterilisation and re-validation downtime.
The author concludes that transitioning to continuous flow manufacturing will reduce unit production costs by at least 20 percent based on eliminating cleaning and re-validation downtime. For this conclusion to hold, the financial benefit of eliminating downtime must not be neutralized by new costs inherent to continuous flow manufacturing. If maintenance or operational expenses specific to continuous flow equipment equal or exceed the savings gained from eliminating downtime, the overall cost per unit will not fall by 20 percent. Therefore, the assumption that continuous flow maintenance costs will not offset downtime savings is necessary for the conclusion to stand.

Step-by-Step Solution

1
Identify the premise and conclusion of the argument.
Premise: Continuous flow manufacturing eliminates multi-day downtime needed for vessel cleaning and re-validation between batches. Conclusion: Transitioning to continuous flow manufacturing will reduce overall unit production costs by at least 20 percent.
Deconstructing the argument isolates the evidence from the primary claim.
2
Identify the logical leap between premise and conclusion.
The argument assumes that eliminating downtime savings directly translates to net cost reductions without introducing offsetting expenses.
Gross savings in one operational area only yield net savings if new costs elsewhere do not absorb those savings.
3
Apply the Negation Test to evaluate candidate assumptions.
Negating the statement regarding maintenance costs reveals that if continuous flow maintenance costs equal or exceed downtime savings, unit costs cannot drop by 20 percent. The argument collapses.
A required assumption must shatter the conclusion when logically negated.

Key Concept

Identifying unstated necessary assumptions in GMAT Critical Reasoning using the Negation Test.
Estimated Time:2m 0s
Question 16Question →

Consider the following argument: A deep-sea oceanographic research institute plans to replace its fleet of battery-powered autonomous gliders with thermal-gradient gliders for long-term polar climate monitoring. The battery-powered gliders require frequent, expensive ship-based retrieval trips to replace depleted batteries. Because thermal-gradient gliders harvest energy from oceanic temperature differences, they can remain deployed indefinitely, thereby eliminating retrieval trips. The institute concludes that this transition will significantly lower its total operating cost per oceanographic data point collected over a five-year period.

Statement: For the institute's conclusion to hold, it must be assumed that the capital and maintenance costs unique to operating thermal-gradient gliders over five years will not exceed the financial savings achieved by eliminating ship-based battery replacement trips.

Show answer & explanation

Answer: True

Answer

True. The claim represents a necessary unstated assumption because if the unique capital and maintenance costs of thermal-gradient gliders exceed the savings from eliminated ship trips, the overall operating cost per data point over five years will not decrease.
The statement is correct (True) because an argument concluding that overall cost will decrease after eliminating one expense implicitly relies on the assumption that no new expenses equal to or greater than the savings will be introduced. Applying the Negation Test confirms that if new costs exceed saved costs, the conclusion fails.

Step-by-Step Solution

1
Deconstruct the core argument components.
Premise: Battery replacement requires costly ship trips. Premise: Thermal gliders eliminate ship trips by harvesting oceanic energy. Conclusion: Transitioning to thermal gliders will reduce total operating cost per data point over five years.
Isolating the premise-to-conclusion link clarifies the gap between eliminating one specific expense and reducing overall cost.
2
Identify the logical shift or gap.
The premises show a reduction in ship retrieval expenses, but the conclusion makes a broad claim about total operating cost over a five-year timeframe.
Total cost includes all expenses (capital acquisition, maintenance, payload integration), not just retrieval logistics.
3
Apply the Negation Test to the statement.
Negated statement: The capital and maintenance costs unique to thermal-gradient gliders DO exceed the savings from eliminating ship trips.
Testing the logical contradiction determines whether the assumption is strictly necessary.
4
Evaluate the impact of the negated statement on the conclusion.
If extra equipment costs outweigh retrieval savings, the total operating cost per data point will increase or stay equal, completely invalidating the institute's conclusion.
Since negating the statement breaks the argument, the statement is a required unstated assumption.

Key Concept

Identifying Unstated Assumptions via the Negation Test
Question 17Question →

Consider the following argument: An agricultural technology firm has developed a novel bio-inoculant containing engineered rhizobacteria designed to increase wheat root depth, thereby improving crop drought tolerance. Field trials conducted exclusively in sandy loam soils demonstrated a 25 percent increase in wheat grain yields under severe drought conditions. Based on these trial results, the firm concludes that commercial application of this bio-inoculant across all major wheat-growing regions will reliably protect wheat yields against severe droughts.

Statement: The argument relies on the unstated assumption that the rhizobacteria bio-inoculant will achieve similar root-depth enhancements in non-sandy soil types typical of other major wheat-growing regions.

Show answer & explanation

Answer: True

Answer

True. The argument assumes that the performance demonstrated in sandy loam soil during field trials will translate to non-sandy soil types found across other wheat-growing regions.
The argument bases its broad prediction about all major wheat-growing regions on field trials conducted solely in sandy loam soils. To logically connect this specific evidence to the overall conclusion, the author must assume that the bio-inoculant's effectiveness is not restricted to sandy loam soils. Applying the Negation Test demonstrates this dependency: if the bio-inoculant does not enhance root depth in non-sandy soil types, widespread commercial application across all regions cannot reliably protect yields, thereby invalidating the argument.

Step-by-Step Solution

1
Deconstruct the argument into premise and conclusion.
Premise: Field trials in sandy loam soils showed a 25% yield increase under severe drought conditions using the bio-inoculant. Conclusion: Commercial application across all major wheat-growing regions will reliably protect wheat yields against severe droughts.
Separating the specific evidence from the broad claim highlights the logical gap between the trial conditions and the global target market.
2
Identify the scope shift between the premise and conclusion.
The premise is restricted to 'sandy loam soils', whereas the conclusion extends to 'all major wheat-growing regions', which contain diverse non-sandy soil compositions.
A necessary assumption must bridge the gap between the tested soil environment and untested soil environments.
3
Apply the Negation Test to the evaluated statement.
Negated Statement: The bio-inoculant will NOT achieve similar root-depth enhancements in non-sandy soil types typical of other major wheat-growing regions. If this negated claim is true, the broad commercial deployment will fail in regions with non-sandy soil, directly invalidating the conclusion that yields will be reliably protected across all major regions.
Because negating the statement destroys the argument's conclusion, the statement is a required unstated assumption.

Key Concept

Identifying Necessary Unstated Assumptions via the Negation Test
Question 18Question →

Consider the following argument: Urban atmospheric pollution accelerates the decay of historic stained-glass windows through chemical corrosion. To protect a landmark cathedral's 14th-century windows, conservators propose installing protective secondary glazing panels on the exterior facade. Because these panels block airborne sulfur compounds and regulate surface humidity, conservators conclude that this intervention will significantly decrease the overall rate of deterioration experienced by the historic glass over the next decade.

True or False: The argument relies on the unstated assumption that the physical installation of the secondary glazing panels will not introduce mechanical damage or structural strain to the historic glass that offsets the reduction in chemical deterioration.

Show answer & explanation

Answer: True

Answer

True. The argument depends on the unstated assumption that the installation process will not introduce mechanical damage that offsets the chemical protection gained.
The author concludes that installing secondary glazing will cause a net decrease in overall glass deterioration based solely on evidence that the panels reduce chemical corrosion. For a net decrease to occur, any negative side-effects resulting from the intervention—such as mechanical damage during installation—must not equal or exceed the chemical damage prevented. Applying the Negation Test confirms that if installation damage offsets the chemical protection, the conclusion fails. Thus, the statement represents a necessary unstated assumption.

Step-by-Step Solution

1
Identify the argument's premise and conclusion.
Premise: Secondary glazing panels block sulfur compounds and regulate humidity, preventing chemical corrosion. Conclusion: Installing the panels will significantly decrease the overall deterioration rate of the historic glass.
Analyzing the scope shift from a specific benefit (chemical protection) to an overall outcome (total deterioration rate) exposes unstated gaps in the logic.
2
Evaluate potential side-effects or implementation gaps.
The argument assumes that achieving the specific chemical benefit will translate directly into a net reduction in overall damage.
If implementing a plan introduces new damage, the net benefit claimed by the conclusion may not be realized.
3
Apply the Negation Test to the statement.
Negated statement: The physical installation WILL introduce mechanical damage or structural strain that offsets the reduction in chemical deterioration. Outcome: The conclusion that overall deterioration will significantly decrease is completely undermined.
A statement whose logical negation invalidates the main conclusion is a necessary unstated assumption of the argument.

Key Concept

Negation Test for Necessary Assumptions
Question 19Question →

Consider the following argument: A municipal building authority plans to replace the conventional steam radiator heating systems in its historic administrative offices with low-temperature geothermal heat pumps. The authority claims that this modification will reduce total heating expenses for these buildings over the next decade because geothermal systems consume significantly less grid electricity per unit of thermal energy delivered than electric boiler steam systems.

True or False: The argument depends on the assumption that the total cost of installing and maintaining the geothermal heat pump system over the next decade will not exceed the monetary savings gained from reduced electricity consumption.

Show answer & explanation

Answer: True

Answer

True. The argument logically depends on the unstated assumption that installation and maintenance costs will not negate the energy cost savings over the ten-year period.
The author infers a reduction in overall ten-year heating expenses solely from a premise establishing that geothermal systems use less electricity per unit of heat. For operational energy efficiency to lead to lower total financial expenditure over time, non-operational costs—specifically initial system purchase, installation, and routine maintenance—must not exceed the monetary value of the energy saved.

Step-by-Step Solution

1
Identify the argument's premise and conclusion.
Premise: Geothermal heat pumps consume less electricity per unit of heat than electric boilers. Conclusion: Replacing the system will decrease total heating expenses over the next decade.
Isolating the gap between lower energy consumption and lower overall financial expenditure reveals unstated assumptions.
2
Apply the Negation Test to the candidate assumption.
Negated claim: The total cost of installing and maintaining the geothermal system over the next decade WILL exceed the savings from reduced electricity consumption.
Negating a necessary assumption tests whether the author's conclusion can survive without it.
3
Assess the logical impact of the negated statement on the author's conclusion.
If initial installation and ongoing maintenance costs outweigh energy savings, total heating expenses over ten years will increase, falsifying the conclusion.
A statement is a required unstated assumption if its logical negation renders the conclusion untenable.

Key Concept

The Negation Test for Identifying Necessary Assumptions
Question 20Question →

To reduce water waste, a major agricultural cooperative plans to equip all member farms with automated soil-moisture sensors that trigger irrigation only when soil moisture falls below a critical threshold. The cooperative claims that implementing this system across all member farms will significantly decrease total regional water consumption for agricultural irrigation over the next five years.

Which of the following is an assumption on which the agricultural cooperative's claim depends?

Show answer & explanation

Answer: Farmers participating in the cooperative will not substantially expand their irrigated crop acreage in response to the water savings provided by the sensors.

Answer

The argument depends on assuming that farmers participating in the cooperative will not substantially expand their irrigated crop acreage in response to the water savings provided by the sensors.
The argument relies on a leap from per-farm technological efficiency to a net decrease in total regional water volume. The correct answer identifies a necessary assumption regarding farm behavior: if farmers respond to per-acre water savings by expanding their total irrigated crop acreage, the volume of water consumed across the expanded cropland could offset any efficiency gains. Negating this choice shatters the author's conclusion, proving it is a required unstated assumption.

Step-by-Step Solution

1
Identify the argument structure (premises and conclusion)
Premise: Automated soil-moisture sensors irrigate only when soil moisture drops below a threshold. Conclusion: Implementing this system across all member farms will decrease total regional water consumption for agricultural irrigation.
Understanding the logic gap between sensor-level efficiency and total regional water volume is required to locate the unstated assumption.
2
Identify potential logical gaps or rebound effects
Per-acre efficiency gains might be cancelled out if total cultivated area increases (a classic rebound effect).
Total volume consumed depends on both per-acre usage rate and total acres irrigated.
3
Apply the Negation Test to the correct option
Negated statement: 'Farmers WILL substantially expand their irrigated crop acreage in response to water savings.' If acreage expands, total water used across the larger area could equal or exceed original levels, causing the conclusion to collapse.
A statement is a necessary assumption if its logical negation invalidates the argument's conclusion.

Key Concept

Negation Test for Unstated Assumptions
Page 1 / 2Next