Inference and Deduction

215 questions

Question 61Question →

Under the revised municipal zoning regulations, a geothermal energy facility will be granted a commercial operating permit only if it incorporates advanced seismic monitoring equipment and operates within a strict noise threshold.

Based on these regulations, it is logically valid to conclude that if a geothermal energy facility is not granted a commercial operating permit, it must be the case that it either failed to incorporate advanced seismic monitoring equipment or failed to operate within a strict noise threshold.

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Answer: False

Answer

False
The conclusion is logically invalid because it commits the fallacy of Mistaken Negation. The original premise establishes that the equipment and noise threshold are necessary conditions for a permit. The stem incorrectly infers that lacking a permit guarantees a failure to meet these specific conditions, ignoring the fact that the permit could easily be denied for other reasons.

Step-by-Step Solution

1
Diagram the formal logic in the original premise.
Permit Granted → (Seismic Equipment AND Noise Threshold)
The phrase 'only if' introduces necessary conditions, which must be placed on the right side of the conditional arrow.
2
Form the valid contrapositive of the original premise.
(No Seismic Equipment OR No Noise Threshold) → No Permit Granted
To form a valid contrapositive, reverse the terms, negate them, and apply De Morgan's laws to change 'AND' to 'OR'.
3
Diagram the logical relationship asserted in the stem's conclusion.
No Permit Granted → (No Seismic Equipment OR No Noise Threshold)
Translating the proposed inference allows for direct comparison with the valid contrapositive.
4
Compare the asserted conclusion to the valid contrapositive.
The asserted conclusion is a Mistaken Negation of the original premise.
The conclusion improperly treats the necessary conditions as if they were sufficient, making the logical inference invalid.

Key Concept

Distinguishing a valid contrapositive from a Mistaken Negation when evaluating compound conditional statements.
Question 62Question →

Botanical researchers studying the Aquilaria tree have confirmed that its production of agarwood—a dense, resinous heartwood—is an immunological response to a specific fungal infection. In Aquilaria trees that have never been infected, the heartwood remains light and completely odorless. Experimental inoculations revealed that the final total volume of agarwood produced by an infected tree is determined exclusively by the number of distinct fungal infection sites on its trunk. However, the researchers also observed that the ambient humidity of the tree's environment dictates the speed at which the fungus spreads; this spread rate directly determines how rapidly the tree initiates its resin production.

Which one of the following is most strongly supported by the researchers' findings?

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Answer: Two Aquilaria trees grown in environments with entirely different ambient humidity levels could nonetheless produce the same final volume of agarwood.

Answer

Two Aquilaria trees grown in environments with entirely different ambient humidity levels could nonetheless produce the same final volume of agarwood.
The correct statement is logically derived from the explicit rules in the stimulus. The text states that the final total volume of agarwood is determined 'exclusively' by the number of distinct fungal infection sites. It also states that ambient humidity dictates the 'speed' of the spread and how rapidly production initiates. Because humidity only affects the timeline and the final volume is governed exclusively by infection sites, it is entirely possible for two trees in different humidity environments to have the same number of infection sites and, consequently, the exact same final volume of agarwood.

Step-by-Step Solution

1
Analyze the premises provided in the stimulus.
Identified two independent relationships: 1) Final volume of agarwood is exclusively determined by the number of infection sites. 2) Ambient humidity determines the speed of fungal spread and how rapidly resin production begins.
Deconstructing the stimulus into individual facts is required to see what can be logically proven.
2
Evaluate the relationship between volume, infection sites, and humidity.
Humidity affects the rate of production but has no stated effect on the final volume, which is strictly governed by the number of infection sites.
Understanding the boundaries of these causal rules allows us to synthesize a valid inference.
3
Assess the correct statement against the established relationships.
The correct statement is fully supported because two trees with different humidity levels (affecting only speed) could have the same number of infection sites, resulting in the same final volume.
The correct answer must be provable based strictly on the text, without assuming outside information.

Key Concept

Synthesizing independent rules to determine what must or could be true, while carefully distinguishing between factors that affect rate versus those that affect total quantity.
Question 63Question →

A long-term study of commercial vineyards found that every vineyard that successfully eliminated powdery mildew over the last decade had implemented a high-density canopy management system. The study also showed that among the vineyards utilizing high-density canopy management, only those that simultaneously applied sulfur-based bio-fungicides experienced a measurable increase in overall grape yield. Furthermore, several vineyards applied sulfur-based bio-fungicides without implementing high-density canopy management; while these vineyards saw a measurable increase in overall grape yield, they failed to eliminate powdery mildew.

Statement: Based on the study, it is most strongly supported that the application of sulfur-based bio-fungicides is a sufficient condition for a vineyard to experience a measurable increase in overall grape yield.

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Answer: False

Answer

False
The proposed inference incorrectly identifies a necessary condition and a partial observation as a universal sufficient condition. The stimulus states that among vineyards with high-density canopies, 'only those' with bio-fungicides increased yields (making the fungicide necessary, not sufficient). Furthermore, the observation that 'several' vineyards with fungicides but no canopy management also increased yields provides evidence for 'some', but fails to establish a universal guarantee. Therefore, the statement is logically unsupported.

Step-by-Step Solution

1
Analyze the conditional relationship between canopy management and eliminating mildew.
Eliminating powdery mildew requires high-density canopy management.
The text states that 'every vineyard that successfully eliminated powdery mildew... had implemented' the canopy system.
2
Analyze the conditional relationship between bio-fungicides, canopy management, and grape yield.
For vineyards with high-density canopies, increased yield requires sulfur-based bio-fungicides.
The text states 'among the vineyards utilizing [the canopy system], only those that simultaneously applied [bio-fungicides] experienced a measurable increase'.
3
Evaluate the evidence regarding vineyards with bio-fungicides but without canopy management.
Some (several) vineyards with bio-fungicides and without the canopy system experienced increased yields.
The text explicitly mentions 'several' such vineyards achieved this, establishing a 'some' statement rather than an 'all' statement.
4
Compare the synthesized logical rules against the proposed statement.
The statement incorrectly claims applying bio-fungicides is sufficient to guarantee increased yield.
The premises only establish bio-fungicides as a necessary condition in one specific context, and as being present in 'several' successful cases in another context. It is never established as a universal guarantee (sufficient condition).

Key Concept

Distinguishing between necessary conditions, sufficient conditions, and existential qualifiers ('some' vs. 'all') when evaluating logical inferences.
Estimated Time:1m 45s
Question 64Question →

A cybersecurity firm's incident response protocol is governed by several conditional rules. To establish a valid deductive chain proving that 'If an anomaly is detected in the network, then the CEO must be notified,' arrange the following protocol rules in their correct logical sequence from the initial sufficient trigger to the final necessary outcome.

Drag items to arrange them in the correct order

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Answer

The correct deductive chain starts with the detection of an anomaly and ends with notifying the CEO, ordering the rules as follows: 1) Any detection of an anomaly... 2) A Level 1 diagnostic is not initiated unless... 3) The automated defense system... 4) The CISO is alerted only if...
The correct sequence translates the English rules into a continuous transitive chain: Anomaly -> Diagnostic -> Lockdown -> CISO -> CEO. Each step perfectly links the necessary condition of the previous statement as the sufficient condition of the next, utilizing proper translations for 'requires', 'unless', 'sufficient', and 'only if'.

Step-by-Step Solution

1
Identify the initial trigger from the prompt ('anomaly is detected') and find the rule that uses it as a sufficient condition.
Rule: 'Any detection of an anomaly... requires the initiation of a Level 1 diagnostic.' (Anomaly -> Diagnostic).
The prompt requires starting the chain with the anomaly detection. 'Requires' indicates the diagnostic is necessary.
2
Find the rule that uses the necessary condition from the first step (Diagnostic) as its sufficient condition.
Rule: 'A Level 1 diagnostic is not initiated unless the automated defense system triggers a full lockdown.' (Diagnostic -> Lockdown).
The logical translation of 'Not A unless B' is 'If A then B', which perfectly chains from the previous step.
3
Find the rule that uses the necessary condition from the second step (Lockdown) as its sufficient condition.
Rule: 'The automated defense system triggering a full lockdown is sufficient to alert the CISO.' (Lockdown -> CISO).
The word 'sufficient' explicitly marks the lockdown as the trigger for alerting the CISO.
4
Find the rule that concludes the chain with the final necessary outcome ('CEO must be notified').
Rule: 'The CISO is alerted only if the CEO is formally notified...' (CISO -> CEO).
The phrase 'only if' introduces the necessary condition, providing the final required outcome of the chain.

Key Concept

Translating formal logic indicators (requires, unless, sufficient, only if) to build multi-step conditional chains.
Question 65Question →

According to university policy, a student cannot register for the advanced robotics seminar unless they have completed the introductory physics course. Furthermore, no student can complete the introductory physics course without receiving a passing grade on the physics final exam.

Which of the following logically follows from the statements above?

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Answer: Any student who registers for the advanced robotics seminar has received a passing grade on the physics final exam.

Answer

Any student who registers for the advanced robotics seminar has received a passing grade on the physics final exam.
The stimulus provides two conditional rules that can be logically chained. The first rule, using the 'unless' indicator, translates to: If a student registers for the advanced seminar, they must have completed the introductory course. The second rule, using 'no... without', translates to: If a student completes the introductory course, they must have passed the final exam. Linking these (Register -> Complete -> Pass) yields the valid deduction that anyone who registers must have passed the final exam.

Step-by-Step Solution

1
Translate the first sentence into formal logic.
Register for Advanced Seminar -> Complete Introductory Course
The word 'unless' introduces a necessary condition. 'Cannot [X] unless [Y]' translates to 'If [X], then [Y]'.
2
Translate the second sentence into formal logic.
Complete Introductory Course -> Pass Final Exam
The phrase 'no... without' means the second part is necessary for the first. 'No [X] without [Y]' translates to 'If [X], then [Y]'.
3
Chain the conditional statements together.
Register for Advanced Seminar -> Complete Introductory Course -> Pass Final Exam
Because the necessary condition of the first statement matches the sufficient condition of the second statement, they can be linked transitively.
4
Derive the logical inference.
Register for Advanced Seminar -> Pass Final Exam
The transitive property of conditionals allows skipping the middle term to form a new valid conditional.

Key Concept

Diagramming Conditional Statements
Question 66Question →

According to the new city zoning regulations, a commercial development permit will be approved only if the proposed building features a public green space and adheres strictly to the district's height restrictions. Furthermore, a building cannot adhere to these height restrictions unless its architectural plans undergo a rigorous environmental review.

If the statements above are true, which one of the following must also be true?

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Answer: If the architectural plans for a proposed building do not undergo a rigorous environmental review, then a commercial development permit will not be approved for it.

Answer

If the architectural plans for a proposed building do not undergo a rigorous environmental review, then a commercial development permit will not be approved for it.
The correct answer accurately forms the contrapositive of the logical chain provided in the stimulus. By establishing that 'Permit Approved' requires 'Height Restrictions', and 'Height Restrictions' requires 'Environmental Review', we can logically conclude that 'Permit Approved' ultimately requires 'Environmental Review'. The contrapositive of this relationship is that without an environmental review, a permit cannot be approved.

Step-by-Step Solution

1
Diagram the first sentence using the 'only if' indicator.
Permit Approved → Public Green Space AND Adheres to Height Restrictions.
The phrase 'only if' introduces necessary conditions, which go on the right side of the arrow.
2
Diagram the second sentence using the 'cannot... unless' indicator.
Adheres to Height Restrictions → Environmental Review.
The phrase 'unless' introduces a necessary condition. 'Cannot adhere' becomes positive 'Adheres' as the sufficient condition.
3
Link the conditional statements together into a transitive chain.
Permit Approved → Adheres to Height Restrictions → Environmental Review.
Because 'Adheres to Height Restrictions' is necessary for Approval and sufficient for Environmental Review, the chain connects them.
4
Form the contrapositive of the extended conditional chain.
NOT Environmental Review → NOT Permit Approved.
Reversing and negating the ends of the chain yields a valid deduction that matches the correct answer.

Key Concept

Chaining Conditional Statements and Contrapositives
Estimated Time:1m 30s
Question 67Question →

Arrange the following conditional statements in the correct logical sequence to form an unbroken deductive chain, starting from the initial trigger 'the new software is installed' and ending with the final outcome 'the quarterly budget is exceeded'.

Drag items to arrange them in the correct order

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Answer

The correct sequence connects each necessary condition to the next sufficient condition to form the chain: Software is installed -> Server downtime occurs -> Customer complaints increase -> IT department works overtime -> Quarterly budget is exceeded.
The correct sequence accurately translates all conditional indicators into a valid transitive chain. 'Whenever' introduces a sufficient condition (Software -> Downtime). 'Is sufficient to' introduces a sufficient condition (Downtime -> Complaints). 'Requires' introduces a necessary condition (Complaints -> Overtime). 'Only if' introduces a necessary condition (Overtime -> Budget). Connecting these end-to-end forms an unbroken logical path.

Step-by-Step Solution

1
Identify the starting trigger and the final outcome from the prompt.
Start: 'Software is installed'. End: 'Budget is exceeded'.
Establishing the endpoints of the deductive chain helps anchor the ordering process.
2
Translate each English statement into formal 'If -> Then' logic using the conditional indicators.
Link 1: Software -> Downtime. Link 2: Downtime -> Complaints. Link 3: Complaints -> Overtime. Link 4: Overtime -> Budget.
Translating indicators like 'whenever', 'sufficient', 'requires', and 'only if' reveals the underlying logical direction of each statement.
3
Connect the statements by matching the necessary condition (right side) of one to the sufficient condition (left side) of the next.
The chain perfectly aligns as: Software -> Downtime -> Complaints -> Overtime -> Budget.
A valid transitive deductive chain must link overlapping conditions in a continuous sequence without reversing any relationships.

Key Concept

Diagramming and linking conditional statements (Transitive Property)
Question 68Question →

According to the newly published guidelines for the National Architectural Excellence Award, a commercial building is eligible for the highest tier of recognition only if it operates with a net-zero carbon footprint.

Based on the guidelines above, which one of the following statements must be true?

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Answer: If a commercial building does not operate with a net-zero carbon footprint, it is not eligible for the highest tier of recognition.

Answer

The statement expressing that if a commercial building does not operate with a net-zero carbon footprint, it is not eligible for the highest tier of recognition.
The stimulus establishes a conditional relationship using the indicator 'only if'. 'Only if' introduces the necessary condition. Therefore, the logical structure is: Eligible for Highest Tier -> Net-Zero Carbon Footprint. The correct answer accurately represents the contrapositive of this relationship: if the necessary condition is not met (No Net-Zero), then the sufficient condition cannot occur (Not Eligible).

Step-by-Step Solution

1
Identify the conditional indicator and translate the stimulus into formal logic.
The phrase 'only if' introduces a necessary condition. The relationship is: Eligible for highest tier -> Operates with net-zero carbon footprint.
Diagramming the baseline conditional relationship correctly is required to draw valid logical deductions.
2
Form the valid contrapositive of the diagrammed conditional statement.
Negate both sides and reverse the arrow: Does NOT operate with net-zero carbon footprint -> NOT eligible for highest tier.
The contrapositive is logically equivalent to the original statement and is a guaranteed true deduction.
3
Evaluate the answer choices against the valid contrapositive and original statement.
The correct option perfectly matches the contrapositive generated in Step 2.
Valid deductions in formal logic must be completely supported by the premises without assuming outside information or committing formal logical fallacies.

Key Concept

Translating conditional statements using 'only if' and applying the rule of contraposition.
Question 69Question →

According to a national museum's updated curation protocols, an artifact will be exhibited in the Main Gallery only if it undergoes a comprehensive structural restoration. Furthermore, a comprehensive structural restoration requires the direct supervision of the chief conservator. No artifact can be insured for its maximum appraised value unless it is exhibited in the Main Gallery. Finally, any artifact that lacks a verified historical provenance will not receive the direct supervision of the chief conservator. Based on the rules above, which one of the following statements must be true?

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Answer: Any artifact that is insured for its maximum appraised value must possess a verified historical provenance.

Answer

The statement that any artifact insured for its maximum appraised value must possess a verified historical provenance.
The correct answer accurately synthesizes the conditional statements into a single transitive chain. The stimulus establishes that maximum insurance requires Main Gallery exhibition. Main Gallery exhibition requires restoration. Restoration requires the chief conservator's supervision. Finally, if an artifact lacks provenance, it cannot have supervision, which contraposes to: supervision requires provenance. Chaining these together proves that any artifact insured for maximum value must ultimately have a verified provenance.

Step-by-Step Solution

1
Translate the first conditional statement ('only if').
Exhibited in Main Gallery -> Comprehensive Structural Restoration
The phrase 'only if' introduces a necessary condition.
2
Translate the second conditional statement ('requires').
Comprehensive Structural Restoration -> Direct Supervision of Chief Conservator
The word 'requires' introduces a necessary condition.
3
Translate the third conditional statement ('unless').
Insured for Maximum Value -> Exhibited in Main Gallery
The phrase 'No X unless Y' translates to 'If X, then Y' (or 'If not Y, then not X').
4
Translate and contrapose the final conditional statement.
Original: No Verified Provenance -> No Direct Supervision. Contrapositive: Direct Supervision -> Verified Provenance
To connect this statement to the others, we must take its contrapositive by negating and reversing both terms.
5
Synthesize the individual conditional statements into a single transitive chain.
Insured for Maximum Value -> Exhibited in Main Gallery -> Comprehensive Structural Restoration -> Direct Supervision -> Verified Provenance
Because the necessary condition of each rule matches the sufficient condition of the next, they form a continuous deductive chain.
6
Evaluate the options against the synthesized chain to find the valid inference.
The chain proves that 'Insured for Maximum Value -> Verified Provenance', which matches the correct answer.
In a valid conditional chain, the first sufficient condition guarantees the final necessary condition.

Key Concept

Conditional Logic Chaining and Contraposition
Estimated Time:1m 30s
Question 70Question →

Match each conditional statement on the left with its logically valid contrapositive on the right.

Click a left item, then click its matching right item

Items

The treaty will be signed only if both nations compromise.
Winning the championship requires a strong defense.
Unless the budget is increased, the project will fail.
If the alarm sounds, the building must be evacuated and searched.

Matches

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Answer

The correct matches accurately pair each conditional statement with its logically valid contrapositive by reversing the sufficient and necessary conditions, and properly negating both terms.
Each correct pairing takes the original conditional relationship, successfully reverses the sufficient and necessary conditions, and negates both. It also properly applies De Morgan's laws by swapping 'and' to 'or' where applicable.

Step-by-Step Solution

1
Identify the sufficient and necessary conditions in each original statement based on logical indicator words (if, only if, requires, unless).
Translated natural language statements into formal conditional logic.
Standardizing the logical structure is a required first step before manipulating the conditions.
2
Apply the rule of contraposition by reversing the order of the conditions and negating both.
Formed the logically equivalent contrapositive for each simple conditional.
The contrapositive is the only formally valid logical deduction that can always be made from a conditional statement.
3
Apply De Morgan's laws to compound conditionals during the negation process.
Converted the 'and' conjunction to an 'or' disjunction when negating the required conditions for the alarm.
When negating a conjunction (A and B), the negation distributes to both terms and changes the operator to a disjunction (~A or ~B).

Key Concept

Forming Contrapositives
Estimated Time:1m 0s
Question 71Question →

In formal logic, accurately diagramming conditional statements is crucial for deductive reasoning. Let MM represent the statement 'The motion is granted' and SS represent the statement 'A settlement is reached'. Match each legal rule on the left with its correct propositional logic translation on the right.

Click a left item, then click its matching right item

Items

The motion will be granted only if a settlement is reached.
Reaching a settlement ensures that the motion will be granted.
A settlement will be reached unless the motion is granted.
The motion will not be granted if a settlement is reached.

Matches

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Answer

The correct pairings are: 'only if' maps to M→SM \rightarrow S; 'ensures' maps to S→MS \rightarrow M; 'unless' maps to ∼M→S\sim M \rightarrow S; and 'not... if' maps to S→∼MS \rightarrow \sim M.
Each legal rule features a distinct logical indicator that dictates the direction of the conditional relationship. 'Only if' denotes a necessary condition (M→SM \rightarrow S). 'Ensures' acts identically to 'if', marking a sufficient condition (S→MS \rightarrow M). 'Unless' translates to 'if not', negating one term to form the sufficient condition (∼M→S\sim M \rightarrow S). Finally, an 'if' clause in the middle of a sentence still acts as the sufficient condition, and the negated main clause becomes the necessary condition (S→∼MS \rightarrow \sim M).

Step-by-Step Solution

1
Identify the sufficient and necessary conditions for the 'only if' statement.
The motion is granted (MM) is sufficient, and a settlement is reached (SS) is necessary.
The phrase 'only if' immediately precedes the necessary condition.
2
Analyze the statement using 'ensures'.
Reaching a settlement (SS) guarantees the motion (MM), giving S→MS \rightarrow M.
Synonyms for 'if' like 'ensures' or 'guarantees' introduce the sufficient condition.
3
Translate the 'unless' statement into an 'if not' conditional.
The statement becomes 'If the motion is not granted, a settlement will be reached' (∼M→S\sim M \rightarrow S).
The logical equivalent of 'A unless B' is 'If not B, then A'.
4
Determine the trigger and outcome for the 'if' statement containing a negation.
The sufficient condition is 'a settlement is reached' (SS) and the necessary condition is 'the motion will not be granted' (∼M\sim M), yielding S→∼MS \rightarrow \sim M.
The word 'if' introduces the sufficient condition, regardless of where it appears in the sentence.

Key Concept

Diagramming Conditional Statements
Question 72Question →

If a building is designated as a historical landmark, it cannot be demolished. Furthermore, any building that cannot be demolished is exempt from property taxes.

Which one of the following statements must be true based on the information provided?

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Answer: If a building is designated as a historical landmark, it is exempt from property taxes.

Answer

If a building is designated as a historical landmark, it is exempt from property taxes.
The correct answer accurately reflects the transitive property of conditional logic. The stimulus gives us A -> B (Historical Landmark -> Cannot be Demolished) and B -> C (Cannot be Demolished -> Exempt from Taxes). By linking these together, we logically deduce A -> C: if a building is a historical landmark, it is exempt from property taxes.

Step-by-Step Solution

1
Identify and diagram the first conditional premise.
Historical Landmark -> Cannot be Demolished
The text states that being a historical landmark is a sufficient condition for a building being protected from demolition.
2
Identify and diagram the second conditional premise.
Cannot be Demolished -> Exempt from Property Taxes
The text states that not being able to be demolished is a sufficient condition for being tax-exempt.
3
Link the two conditional premises to form a transitive chain.
Historical Landmark -> Cannot be Demolished -> Exempt from Property Taxes
The necessary condition of the first premise matches the sufficient condition of the second premise, allowing them to be chained together.
4
Derive the valid inference from the chain.
Historical Landmark -> Exempt from Property Taxes
By following the chain from the initial sufficient condition to the final necessary condition, we logically conclude that historical landmarks are exempt from property taxes.

Key Concept

Chaining Conditional Statements
Question 73Question →

According to the recently ratified Global Agricultural Trade Pact, a nation is permitted to export genetically modified crops only if it maintains a centralized agricultural registry. Furthermore, maintaining such a registry requires the nation to pass the Environmental Baseline Audit. No nation passes the Environmental Baseline Audit without successfully implementing strict cross-pollination containment protocols. Finally, establishing an independent monitoring commission is prerequisite to successfully implementing these strict cross-pollination containment protocols.

Based on the rules provided, arrange the following conditions in the correct logical sequence to form an unbroken, valid deductive chain. Begin with the initial sufficient condition for the sequence and conclude with the final necessary condition.

Drag items to arrange them in the correct order

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Answer

The correct logical sequence from initial sufficient condition to final necessary condition is: Exporting crops → Maintaining registry → Passing audit → Implementing containment → Establishing commission.
The correct sequence accurately translates each conditional indicator to form an unbroken deductive chain. 'Only if' makes the registry necessary for exporting; 'requires' makes the audit necessary for the registry; 'No... without' makes containment necessary for the audit; and 'prerequisite to' makes the commission necessary for containment. Linking these yields: Export → Registry → Audit → Containment → Commission.

Step-by-Step Solution

1
Translate the first rule involving 'only if'.
Exporting crops → Maintaining registry
The indicator 'only if' introduces a necessary condition. Thus, exporting is the sufficient condition that guarantees a registry is maintained.
2
Translate the second rule involving 'requires'.
Maintaining registry → Passing audit
The word 'requires' introduces a necessary condition. Therefore, maintaining the registry guarantees that the audit has been passed.
3
Translate the third rule involving 'No... without'.
Passing audit → Implementing containment
The phrase 'No X without Y' means Y is necessary for X. Passing the audit is sufficient to know that containment protocols are implemented.
4
Translate the fourth rule involving 'is prerequisite to'.
Implementing containment → Establishing commission
A 'prerequisite' is a necessary condition that must occur first. Therefore, implementing containment protocols guarantees that a commission has been established.
5
Synthesize the individual statements into a single deductive chain.
Exporting crops → Maintaining registry → Passing audit → Implementing containment → Establishing commission
By linking the shared sufficient and necessary conditions from each translated rule, an unbroken sequence is formed.

Key Concept

Translating and chaining conditional statements using varied indicators (only if, requires, no...without, prerequisite to).
Question 74Question →

Match each set of conditional premises with its logically valid chained conclusion or its valid contrapositive.

Click a left item, then click its matching right item

Items

If the meeting is held, the training is conducted. If the training is conducted, the project is approved.
If the training is conducted, the review is completed. If the review is completed, the meeting is held.
If the project is approved, the meeting is held. If the meeting is held, the review is completed.
If the review is completed, the project is approved. If the project is approved, the training is conducted.

Matches

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Answer

The logically valid pairs map each premise set to its direct transitive chain or the contrapositive of that chain.
Each valid pairing is derived by connecting two conditional statements to form a chain (A -> B and B -> C yields A -> C). For two of the pairs, the correct matching item provides the contrapositive of this chain (since A -> C implies ~C -> ~A).

Step-by-Step Solution

1
Analyze the first set of premises.
Chain: Meeting -> Training -> Project. Direct inference: Meeting -> Project. This matches the item stating 'If the meeting is held, the project is approved'.
Transitive logic allows us to bypass the intermediate necessary condition.
2
Analyze the second set of premises.
Chain: Training -> Review -> Meeting. Direct inference: Training -> Meeting. The contrapositive of this inference is 'Not Meeting -> Not Training'.
If the final necessary condition fails, the initial sufficient condition could not have occurred.
3
Analyze the third set of premises.
Chain: Project -> Meeting -> Review. Direct inference: Project -> Review. This matches the item stating 'If the project is approved, the review is completed'.
Linking the conditions yields a direct forward inference.
4
Analyze the fourth set of premises.
Chain: Review -> Project -> Training. Direct inference: Review -> Training. The contrapositive is 'Not Training -> Not Review'.
Reversing and negating the valid direct chain produces a valid contrapositive.

Key Concept

Chaining conditional statements and forming contrapositives
Question 75Question →

According to the newly revised deep-sea exploration safety protocols, a submersible is certified for trench operations only if its hull is constructed using a titanium-carbon matrix. Unless a vessel has an upgraded pressure-compensation system, it cannot be constructed using a titanium-carbon matrix. An upgraded pressure-compensation system is never approved for installation without the vessel passing an acoustic integrity scan. Furthermore, passing the acoustic integrity scan requires the installation of redundant hydrostatic sensors.

Based on the safety protocols described above, which of the following must be true?

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Answer: Any submersible that does not have redundant hydrostatic sensors installed is not certified for trench operations.

Answer

Any submersible that does not have redundant hydrostatic sensors installed is not certified for trench operations.
The correct answer accurately reflects the contrapositive of the entire conditional chain. The stimulus establishes that certification requires a titanium hull (C -> T), which requires an upgraded system (T -> U), which requires an acoustic scan (U -> S), which in turn requires redundant sensors (S -> R). By linking these, we get: Certification -> Redundant sensors (C -> R). The contrapositive of this relationship is: No redundant sensors -> No certification (~R -> ~C).

Step-by-Step Solution

1
Identify and translate the first conditional relationship.
Certified for trench operations (C) -> Titanium-carbon matrix hull (T).
The phrase 'only if' introduces a necessary condition.
2
Translate the second and third conditional relationships.
Titanium-carbon matrix hull (T) -> Upgraded pressure-compensation system (U). Upgraded system (U) -> Acoustic integrity scan (S).
The phrase 'unless' means 'if not', creating the conditional: If not U, then not T (which translates to T -> U). The phrase 'never... without' also creates a necessary condition: U -> S.
3
Translate the final conditional relationship and combine all statements into a chain.
Scan (S) -> Redundant sensors (R). The full chain is: C -> T -> U -> S -> R.
The word 'requires' indicates a necessary condition. Connecting the shared terms creates the full logical progression.
4
Form the contrapositive of the entire chain to find the correct valid deduction.
If not R -> not S -> not U -> not T -> not C. Therefore, lacking redundant sensors means the submersible is not certified.
Correct answers in conditional chain questions often rely on the contrapositive of the relationship between the first and last terms.

Key Concept

Diagramming Conditional Statements and Forming Deductive Chains
Question 76Question →

In the context of international finance regulations, no corporate entity can successfully complete a hostile takeover without securing majority shareholder approval. Furthermore, completing such a takeover is possible only if the entity avoids antitrust litigation. Finally, avoiding antitrust litigation requires that the entity neither holds a monopoly in its primary market nor attempts to merge with its largest competitor.

If the statements above are true, which one of the following must also be true?

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Answer: Any corporate entity that attempts to merge with its largest competitor cannot successfully complete a hostile takeover.

Answer

The statement that any entity attempting to merge with its largest competitor cannot successfully complete a hostile takeover must be true.
This option correctly applies the contrapositive of the conditional chain established in the stimulus. The stimulus establishes that completing a takeover requires avoiding antitrust litigation (Takeover -> Avoid Litigation), and avoiding litigation requires NOT attempting to merge with the largest competitor (Avoid Litigation -> NOT Merge Largest). Chaining these together gives: Takeover -> NOT Merge Largest. The contrapositive is: Merge Largest -> NOT Takeover. This precisely matches the correct option.

Step-by-Step Solution

1
Translate the first two sentences into formal conditional logic.
Takeover -> Majority Approval AND Takeover -> Avoid Litigation.
The phrases 'no... without' and 'only if' introduce necessary conditions for the sufficient condition of successfully completing a hostile takeover.
2
Translate the final sentence into formal conditional logic.
Avoid Litigation -> NOT Monopoly AND NOT Merge Largest.
The word 'requires' introduces necessary conditions, and 'neither... nor' dictates that both conditions must be negated.
3
Chain the conditional statements together.
Takeover -> Avoid Litigation -> NOT Monopoly AND NOT Merge Largest.
Because 'Avoid Litigation' is necessary for 'Takeover' and sufficient for 'NOT Merge Largest', they form an unbroken deductive chain.
4
Form the contrapositive of the chained relationship.
Monopoly OR Merge Largest -> NOT Takeover.
Negating the necessary conditions (and flipping AND to OR) yields a sufficient condition that guarantees the takeover will not be completed.

Key Concept

Diagramming Conditional Statements and Contrapositives
Question 77Question →

A software company has established the following protocol for deploying new applications:

- The code is merged into the main branch only if a beta testing phase is scheduled.
- If the software passes the final security audit, the code is merged into the main branch.
- A beta testing phase is scheduled only if the marketing team has been notified.

Arrange the following events in the correct logical sequence, starting with the initial sufficient condition (the trigger) and ending with the final necessary condition.

Drag items to arrange them in the correct order

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Answer

The correct logical sequence is: The software passes the final security audit, followed by the code being merged, followed by a beta testing phase being scheduled, and finally the marketing team being notified.
By translating the conditional statements accurately (Audit -> Merged; Merged -> Beta; Beta -> Marketing), we can form a valid transitive chain from the initial trigger to the final requirement: Audit -> Merged -> Beta -> Marketing.

Step-by-Step Solution

1
Identify the initial sufficient condition that does not depend on any other event occurring first.
The rule 'If the software passes the final security audit...' makes passing the audit the starting trigger.
The word 'if' introduces a sufficient condition.
2
Determine the necessary condition for the first event.
Passing the audit requires that 'the code is merged into the main branch'.
The result of the 'if' clause forms the necessary condition.
3
Link the second event to its own necessary condition.
The code is merged 'only if a beta testing phase is scheduled', linking the code merge to beta testing.
The phrase 'only if' introduces a necessary condition.
4
Link the third event to its necessary condition.
A beta testing phase is scheduled 'only if the marketing team has been notified'.
This establishes the final link in the transitive logic chain.

Key Concept

Chaining Conditional Statements
Question 78Question →

A pharmaceutical regulatory agency uses the following propositional variables to evaluate clinical trials:

MM: Marketing is approved
TT: Toxicity is low
RR: Regulatory audit is passed
CC: Control group improves

Match each English policy statement with its logically equivalent formal diagram. Note that the correct match may represent either the direct translation or its valid contrapositive.

Click a left item, then click its matching right item

Items

Marketing is approved only if toxicity is low.
Toxicity is low if the regulatory audit is passed.
The control group will not improve unless toxicity is low.
Passing the regulatory audit requires that the control group improves.

Matches

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Answer

Statement 1 matches ∼T→∼M\sim T \rightarrow \sim M; Statement 2 matches ∼T→∼R\sim T \rightarrow \sim R; Statement 3 matches C→TC \rightarrow T; Statement 4 matches ∼C→∼R\sim C \rightarrow \sim R.
Each English statement translates to a specific formal logic relationship based on its indicator words. Finding the correct match requires establishing the base conditional statement and, if the direct translation is not an option, taking its valid contrapositive (reversing and negating both terms).

Step-by-Step Solution

1
Analyze 'Marketing is approved only if toxicity is low.'
Translates to M→TM \rightarrow T. Its contrapositive is ∼T→∼M\sim T \rightarrow \sim M.
The phrase 'only if' always modifies the necessary condition, which belongs on the right side of the arrow.
2
Analyze 'Toxicity is low if the regulatory audit is passed.'
Translates to R→TR \rightarrow T. Its contrapositive is ∼T→∼R\sim T \rightarrow \sim R.
When 'if' is used alone in the middle of a sentence, it modifies the sufficient condition, which belongs on the left side of the arrow.
3
Analyze 'The control group will not improve unless toxicity is low.'
Translates to ∼T→∼C\sim T \rightarrow \sim C. Its contrapositive is C→TC \rightarrow T.
The term 'unless' means 'if not'. Applying this gives: If toxicity is not low (∼T\sim T), the control group will not improve (∼C\sim C).
4
Analyze 'Passing the regulatory audit requires that the control group improves.'
Translates to R→CR \rightarrow C. Its contrapositive is ∼C→∼R\sim C \rightarrow \sim R.
The word 'requires' indicates that the subsequent concept is mandatory, making it the necessary condition (right side of the arrow).

Key Concept

Translating conditional indicator words ('only if', 'if', 'unless', 'requires') into formal logic and deriving their contrapositives.
Question 79Question →

If a frog species inhabits the upper canopy of the rainforest, it must have specialized toe pads. Any frog species that has specialized toe pads is capable of adhering to wet leaves. The blue-legged tree frog is a frog species that inhabits the upper canopy of the rainforest.

Which of the following must be true on the basis of the statements above?

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Answer: The blue-legged tree frog is capable of adhering to wet leaves.

Answer

The blue-legged tree frog is capable of adhering to wet leaves.
The stimulus provides a direct chain of conditional reasoning: Canopy → Toe Pads → Adhere to Wet Leaves. Since we are explicitly told that the blue-legged tree frog is a canopy species, it triggers this entire chain, guaranteeing that it can adhere to wet leaves.

Step-by-Step Solution

1
Identify the conditional relationships presented as facts in the stimulus.
Inhabits upper canopy → Has specialized toe pads. Has specialized toe pads → Capable of adhering to wet leaves.
Mapping the conditional logic is the most reliable way to find deductions that are mathematically certain.
2
Chain the conditional statements together using their shared term.
Inhabits upper canopy → Capable of adhering to wet leaves.
The transitive property of logic allows us to connect the first sufficient condition directly to the final necessary condition.
3
Apply the specific factual premise to the logical chain.
Because the blue-legged tree frog satisfies the sufficient condition (inhabits upper canopy), the necessary condition (capable of adhering to wet leaves) must apply to it.
This guarantees a 100% provable inference, which is required for 'Must Be True' questions.

Key Concept

Must Be True Questions
Question 80Question →

Consider the following premises regarding macroeconomic policy:

Any monetary policy framework that stabilizes inflation over a five-year period must rely on dynamic interest rate adjustments. Frameworks that rely on dynamic interest rate adjustments inherently fail to maintain the predictability of short-term lending rates. Furthermore, a monetary policy framework will not gain unanimous approval from the central banking committee unless it maintains the predictability of short-term lending rates.

Based on the information provided, it must be true that no monetary policy framework that stabilizes inflation over a five-year period will gain unanimous approval from the central banking committee.

Show answer & explanation

Answer: True

Answer

True
The statement is logically true. By chaining the premises together (Stabilizes Inflation → Dynamic Adjustments → Fails Predictability), we establish that stabilizing inflation leads to failing to maintain predictability. The 'unless' rule dictates that Unanimous Approval → Maintains Predictability, which contraposes to Fails Predictability → No Unanimous Approval. Linking the entire chain proves that any framework stabilizing inflation will definitively not gain unanimous approval.

Step-by-Step Solution

1
Translate the first premise into a formal conditional statement.
Stabilizes Inflation (SI) → Dynamic Interest Rate Adjustments (DIRA)
The word 'Any' introduces a sufficient condition, and 'must rely' introduces a necessary condition.
2
Translate the second premise into a formal conditional statement.
DIRA → Fails to Maintain Predictability (~MP)
The statement indicates that relying on dynamic adjustments guarantees the failure to maintain predictability.
3
Translate the third premise into a formal conditional statement.
Unanimous Approval (UACB) → Maintains Predictability (MP)
The phrase 'not [A] unless [B]' translates logically to 'If [A], then [B]'. Here, gaining approval is the sufficient condition and maintaining predictability is the necessary condition.
4
Form the contrapositive of the third premise and chain all conditional statements.
Contrapositive: ~MP → ~UACB. Chain: SI → DIRA → ~MP → ~UACB
To connect the premises, the necessary condition of the second premise (~MP) must trigger the sufficient condition of the third premise. The contrapositive allows this connection.
5
Evaluate the final statement against the logical chain.
The final statement is valid and inherently True.
The logical chain simplifies to SI → ~UACB. The statement 'no monetary policy framework that stabilizes inflation... will gain unanimous approval' perfectly expresses this exact relationship.

Key Concept

Conditional logic chaining and translating 'unless' statements.
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