Q19 - Some species of tarantula make good pets

[ohthatpatrick]

Question Type:
Match the Reasoning

Stimulus Breakdown:
Conclusion: Some T's do not have poison fangs.
Evidence: Some T's make good pets, and nothing with poison fangs makes a good pet.

Answer Anticipation:
This is a perfectly valid inference.

We're given a conditional,
"If you're a good pet, you don't have poison fangs"
and a specific fact to apply it to,
"Some Tarantulas are good pets".

This lets us derive
"Some Tarantulas don't have poison fangs".

We can prephrase that we need an argument in which you're given two premises:
a conditional statement and a fact you can apply it to.

The conclusion should be the legal, derivable idea you get from applying the conditional statement.

If we want to get ourselves better ready for the specific quantified formula with which they presented this stuff, we need

(conditional premise): No P's are G.
(factual premise): Some T's are G.
============================
(conclusion): Not all T's are P.

Correct Answer:
A

Answer Choice Analysis:
(A) Looks good! We can apply the conditional to the fact to derive the conclusion.

(B) Nope, the two premise are both "some" statements. Not worth reading. We needed one conditional premise, one statement of fact.

(C) There is no way to apply the conditional in the 2nd sentence to the fact in the 1st sentence. No need to read further.

(D) There is no way to apply the conditional in the 2nd sentence to the fact in the 1st sentence. No need to read further.

(E) Two conditional premises? We just wanted one. We could stop reading at that point. If you were curious, this conclusion is not valid. The evidence tells us that "If you're in this collection, then you're not by Strawn and not regular meter." We can't derive the idea that "some of Strawn's poems do not have regular meter."

Takeaway/Pattern:
Some key conversions we should have memorized:
Not all A are B = Some A are not-B
.......No X are Y = All X are not-Y

#officialexplanation

[VidaH846]

I wonder is “some A are not C” the same with “some C are not A”？ This seems to me the difference between option A and C.