LSAT 31, Logical Reasoning I, Q21

QUESTION TYPE: Parallel Reasoning

CONCLUSION: Alicia knows that the bank deposit was credited on the date of the transaction.

REASONING: Bank deposits are credited on the date of the transaction only when they are made before 3:00 pm. Alicia knows that the deposit was made before 3:00 pm. 

ANALYSIS: This argument ignores the possibility that Alicia doesn’t know under what conditions bank transactions are credited on the same day. (knowledge flaw)

Further, the argument says that bank transactions are credited only when they occur before 3:00 pm. That’s a necessary condition. It didn’t say that they are always credited if made before 3:00pm. So it’s possible that this bank transaction actually wasn’t credited. (sufficient-necessary flaw)

___________

1. This makes one logical flaw. Only journalists can ask questions but that doesn’t mean that every journalist can ask questions. But it doesn’t make the flaw of knowledge.
2. This makes the sufficient-necessary flaw but not the flaw of knowledge.
3. CORRECT. This makes the sufficient-necessary flaw (it doesn’t say that George will be promoted if Helen resigns). It also makes the knowledge flaw. We don’t know if George knows that he could be promoted if Helen resigns. 
4. This is a good argument. (4 isn’t a prime number, but that’s another story)
5. This is a sort of good argument. More properly, Pat wants to work in a profession where the workers are poorly paid.
    
   Pat might still prefer to receive higher pay, but values working as a social worker more. This doesn’t commit the flaw of knowledge, as Pat likely knows what everyone else knows: social workers don’t earn much.

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