Examkin

Question

Difficulty: HardSufficient Assumption

Match each argument with the sufficient assumption that logically guarantees its main conclusion.

  • Only entities that synthesize proteins can be classified as alive. Prions consist solely of misfolded proteins and lack the cellular machinery to synthesize anything. Therefore, prions are incapable of biological evolution.Only entities classified as alive are capable of biological evolution.
  • Expanding the public transit system requires significant increases in municipal funding. The upcoming referendum, if passed, will strictly cap property taxes. Consequently, if the referendum passes, the public transit system will not be expanded.Municipal funding cannot be significantly increased if property taxes are capped.
  • A valid legal contract requires mutual consideration. The agreement between the corporation and the intern involved the exchange of labor for experience, but no monetary compensation was provided. Thus, the agreement is not a valid legal contract.An agreement lacks mutual consideration if it does not involve monetary compensation.
  • Historically, revolutionary scientific theories are initially rejected by the academic establishment. Dr. Vance's new theory of quantum gravity has been warmly embraced by all major physics journals. Therefore, Dr. Vance's theory is incorrect.No scientific theory is correct unless it is revolutionary.
  • The mayor's proposal will reduce traffic congestion in the downtown area. Any proposal that reduces traffic congestion will ultimately improve the city's air quality. Therefore, the city council will definitively approve the mayor's proposal.The city council approves any proposal that improves the city's air quality.

Answer

Argument 1 pairs with 'Only entities classified as alive...', Argument 2 pairs with 'Municipal funding cannot...', Argument 3 pairs with 'An agreement lacks...', Argument 4 pairs with 'No scientific theory is correct...', and Argument 5 pairs with 'The city council approves...'
Each correct pairing connects an argument to the specific conditional statement that logically bridges the gap between its premises and its conclusion. By translating the text into formal logic (e.g., identifying contrapositives or mapping conditional chains), each matched assumption provides the exact sufficient condition required to make its corresponding argument 100% deductively valid.

Step-by-Step Solution

1
Analyze the prion argument to isolate the missing logical link.
The premises prove prions are 'not alive'. The conclusion states they are 'incapable of evolution'. The required bridge is 'not alive -> incapable of evolution' or its contrapositive 'capable of evolution -> alive'.
Identifying the exact deductive gap is the first step in recognizing a sufficient assumption.
2
Analyze the referendum argument's conditional logic.
Premises: Expand -> Increase Funding. Referendum -> Capped Taxes. Conclusion: Referendum -> Not Expand. We must bridge 'Capped Taxes' to 'Not Increase Funding'.
Chaining conditional statements reveals precisely where the argument's logic breaks down.
3
Identify the missing trigger in the contract argument.
We need to prove the agreement lacks mutual consideration to invoke the rule that it is not a valid contract. The assumption must state that 'no monetary compensation' guarantees a 'lack of mutual consideration'.
Sufficient assumptions often serve to trigger a pre-existing conditional premise.
4
Evaluate the contrapositives in the scientific theory argument.
Vance's theory was not rejected, so it is not revolutionary. To conclude it is incorrect, we need 'Not revolutionary -> Incorrect'. This is the contrapositive of 'Correct -> Revolutionary' (No theory is correct unless it is revolutionary).
Translating 'unless' statements into standard 'if-then' conditional formatting is necessary to test validity.
5
Complete the causal/conditional chain for the mayor's proposal.
The premises lead to the fact that the proposal will improve air quality. To conclude approval, the assumption must state that improving air quality is sufficient to guarantee council approval.
Linking the final derived premise to the conclusion is the standard method for solving bridging assumption questions.

Key Concept

Identifying deductive gaps and supplying the exact formal logic conditional (or its contrapositive) that makes the conclusion 100% valid.
Rate this question

Topics

Sufficient Assumption

More questions from this topic