PowerScore LSAT Logical Reasoning Bible - page 115-116

[Ssouki]

Hello!

As I was going through the LR bible, I came across a question with a stimulus that mentions the following, "one danger that has not been given sufficient attention is that these holes could lead to severe eye damage for animals of many species." The question stem is a 1st family, most strongly supported question: "Which one of the following is most strongly supported by the statements above if true?"

Answer choice B states that, "Few species of animals live on a part of the earth's surface that is not threatened by holes in the ozone layer." The explanation on why it is an incorrect answer is, "we know that MANY animals could suffer severe eye damage, and from this we can infer that SOME of them live in areas threatened by holes in the ozone layer. We do NOT know that FEW of the species live in non-threatened areas."

My questions are:

1) Why did you infer that "some live in threatened areas" instead of "many" considering the fact that "many" was mentioned in the stimulus and not "some"?
2)And also can we say that if "many do live in threatened areas", it does not mean that "few live in non-threatened" since many animals can be living in non-threatened too?
3) What if the answer choice was: "Some species of animals live on a part of earth's surface that is not threatened by holes in ozone layer." Would that be correct?

I appreciate your anticipated help!!
Sara

[Jonathan Evans]

Hi, Sara!

Excellent questions. Thank you for sharing your thought process and analysis.

Let's make note of what we know from this stimulus.

1. Ozone filters out some wavelengths of light.
2. Ozone allows other wavelengths through.
3. Holes in the ozone layer could cause severe eye damage for many species.

Combine points (1) and (3) to make a prephrase:

• Wavelengths filtered by ozone could be connected to eye damage for some animals.

Prephrases for Must Be True questions are inherently somewhat conservative in that you should attempt to notice connections in the information given in the stimulus but remain cautious not to overstate your case or go too far. Remember that extreme language is a hallmark of incorrect Must Be True answer choices.

Let's address your questions:

1) Why did you infer that "some live in threatened areas" instead of "many" considering the fact that "many" was mentioned in the stimulus and not "some"?

"many" and "some" are for all intents and purposes on the LSAT equivalent concepts. This concept is discussed in detail on pages 402-403 of the 2017 Logical Reasoning Bible. Make note of the terms that are equivalent to "some" at the bottom of page 403.

Briefly, the concept is that "some" signifies some indeterminate quantity. "Some" of something could mean seven; it could mean seven hundred; it could mean seven million, as in "some Americans are Dallas Cowboys fans."

The term "many" is also indeterminate. "Many" does not mean most. The only lower bound on "many" is one or none. "Many" could be consistent with any other amount of something, any amount greater than one for the purposes of the LSAT. This is the same as "some."

2)And also can we say that if "many do live in threatened areas", it does not mean that "few live in non-threatened" since many animals can be living in non-threatened too?

There is no relationship between the statements "many live in threatened areas" and "few live in non-threatened areas." Consider the range of possibilities for "many live in threatened areas":

1. All animals live in threatened areas.
2. Most animals live in threatened areas.
3. Some animals live in threatened areas.

None of these three statements contradicts "many animals live in threatened areas." Since all of the above statements are possible, it is impossible for us to infer how many live in non-threatened areas. In the case of statement (1) above, none would live in non-threatened areas. In the case of statement (3), it is possible that many or even most animals live in non-threatened areas.

Thus, you are correct that it is quite possible (but not necessary) that many live in non-threatened areas.

3) What if the answer choice was: "Some species of animals live on a part of earth's surface that is not threatened by holes in ozone layer." Would that be correct?

As discussed in the response to the question above, this is not correct. As we noted, the statements "many animals are threatened" and "all animals are threatened" do not contradict each other.

For example, we could say "many swans are white." We can also say "all swans are white." There is no contradiction between these two statements.

Therefore, if we know that "many animals live in threatened areas," we do not know whether any live in non-threatened areas.

Very good questions. I hope this helps.

[Ssouki]

That was very helpful! Thank you so much for the detailed explanation! I appreciate it.