#22 - Radio airplay restrictions are nationally imposed

[CRWalk]

I understand that B matches the stimulus, but I’m having trouble understanding if the argument is valid or invalid (and whether the other answer choices are valid or invalid). Is the argument valid? Which answer choices are invalid? Thanks!

[lsat12345]

It's a valid argument. The question stem will always tell you if it's invalid in a parallel flaw question. All of the guidelines except for 2 particular ones are accounted for. The radio guideline is not one of those two guidelines that are not accounted for, so it IS accounted for.

[Brook Miscoski]

CRWalk,

It's valid reasoning:

Rules:
Radio Regs National
National & -Tax & -Labor Guide
Radio Regs -Tax & -Labor

Conclusion:
Radio Regs Guide

You can look at the first and third rules and see that they create:
Radio Regs National & -Tax & -Labor,

and from that it follows that the Radio Regs are in the Guide.

It is also possible to read the stimulus as providing that all national regs are in the guide except for two kinds. Since the Radio regs aren't one of the two, the radio regs aren't an exception, and are included in the guide. The diagram is a more formal approach to the same reasoning.

[teezoTD]

I'm confused. Can someone explain why the correct answer is B and not A? I can't seem to differentiate the two answer choices.

[Jeff Wren]

Hi teezo,

This argument involves conditional reasoning, and you should definitely diagram this one out. It should really help identify the correct answer from the others, as only the correct Answer B has the exact same form of diagram as the stimulus.

In the stimulus, we get a conditional statement in the second sentence that the City Club has a guide with all nationally imposed regulations except those involving taxation or labor law.

You could diagram this:

NIR and Not T and Not LL -> G

(meaning if something is a nationally imposed regulation and is not taxation, and not labor law, then it is in the guide)

We are told that radio airplay restrictions are nationally imposed regulations, and are not related to taxation or labor law. (In other words, the radio airplay restrictions have satisfied the sufficient condition). The argument concludes that radio airplay restrictions are in the guide (In other words, the necessary occurs.)

This is a valid argument.

Answer B follows the exact same pattern.

We are told that the Garden Club gives awards to all perennials except shrubs or those not native to North America.

You could diagram this:

P and Not S and NNA -> GCAP

(meaning if something is a perennial and not a shrub and is native to North America, then the Garden Club will award a prize for it)

We are told that coreopsis is a perennial, not a shrub, and is native to North America. (In other words, coreopsis has satisfied the sufficient condition). The argument concludes that the Garden Club will award a prize for coreopsis. (In other words, the necessary occurs.)

If you compare the diagram of Answer B with the stimulus, they are exactly the same form (you could swap the terms one for one).

As for Answer A, it changes terms in the middle of the argument. The argument starts off talking about prepackaged desserts, but then switches to prepackaged snack foods. These are not the same and should be diagrammed as different terms. If you do this, you will see that the terms to do not match up and link together as they did in the stimulus and Answer B. Also, because the terms do not match up, Answer A is not valid while the stimulus and Answer B are valid.