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Difficulty: HardMust Be True / Most Strongly Supported

Every industrial facility that implements closed-loop solvent recycling reduces its hazardous wastewater discharge by more than 80 percent. No industrial facility operating in the river basin reduced its hazardous wastewater discharge by more than 80 percent last year unless it received a green modernization subsidy from the municipal environmental authority. Furthermore, any facility that received a green modernization subsidy was subject to unannounced quarterly compliance audits. Apex Chemical, an industrial facility operating in the river basin, was not subject to unannounced quarterly compliance audits last year.

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

  1. A
    Any industrial facility in the river basin that was subject to unannounced quarterly compliance audits last year implemented closed-loop solvent recycling.
  2. B
    Every industrial facility in the river basin that received a green modernization subsidy last year reduced its hazardous wastewater discharge by more than 80 percent.
  3. Apex Chemical did not implement closed-loop solvent recycling last year.Answer
  4. D
    No industrial facility operating outside the river basin received a green modernization subsidy last year.
  5. E
    Apex Chemical failed to comply with the municipal environmental authority's hazardous wastewater regulations last year.

Answer

Apex Chemical did not implement closed-loop solvent recycling last year.
The correct inference strictly follows from contrapositive deduction along the conditional chain. The stimulus establishes that for any facility operating in the river basin, implementing closed-loop solvent recycling guarantees a wastewater discharge reduction of over 80 percent, which in turn requires receiving a green modernization subsidy, which in turn requires being subject to unannounced quarterly compliance audits. Because Apex Chemical operates in the basin and was not subject to quarterly audits, it could not have received the subsidy, could not have achieved the discharge reduction, and therefore could not have implemented closed-loop solvent recycling.

Step-by-Step Solution

1
Map the conditional statements in the stimulus into formal logical relationships.
Statement 1: Closed-Loop Recycling →\rightarrow Discharge Reduction >80%>80\%. Statement 2 (for basin facilities): Discharge Reduction >80%→>80\% \rightarrow Modernization Subsidy. Statement 3: Modernization Subsidy →\rightarrow Quarterly Audits.
Establishing the precise direction of conditional requirements allows for valid contrapositive chaining.
2
Chain the conditional statements for an industrial facility operating in the river basin.
For any basin facility: Closed-Loop Recycling →\rightarrow Discharge Reduction >80%→>80\% \rightarrow Modernization Subsidy →\rightarrow Quarterly Audits.
Combining the premises establishes that undergoing quarterly audits is a necessary condition for any basin facility that implemented closed-loop recycling.
3
Apply the contrapositive to the factual information provided about Apex Chemical.
Apex Chemical is in the river basin and was NOT subject to quarterly audits. By contrapositive: Not Audited →\rightarrow No Subsidy →\rightarrow No Discharge Reduction >80%→>80\% \rightarrow No Closed-Loop Recycling.
Denying the necessary end condition guarantees the denial of all preceding sufficient conditions in the chain.

Key Concept

Multi-premise conditional deduction via contrapositive chaining
Estimated Time:1m 45s
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Topics

Must Be True / Most Strongly Supported

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