19. Within this LSAT passage, note in the first sentence that the Forester states, "great majority". Ignore the "great", but keep the "majority", which means greater than half, or most. Also note in the final sentence that a conditional statement appears:
| Fragmented Forest Maintains Full Complement of Plant and Animal Species g Regular Interventions | |
Choice (A) also provides a conditional statement:
No one Intervenes (i.e., Regular Interventions) g Most Forests Lose 1+ Species (i.e., Fragmented Forest Maintains FullComplement of Plant and Animal Species)
By combining the first sentence with the contrapositive of the final sentence, we know that (A) must be true, and is the correct choice.
(B) provides a conditional statement:
Many of Most Endangered Species Survive g Regular Interventions in Most Remaining Forests |
The passage does not support this. Based on the passage, it's possible that "many" (2+) of the world's most endangered species survive, yet less than "most" of the remaining forests do not have regular interventions. Suppose 49% of the world's remaining forests receive regular intervention and this is sufficient for "many" of the world's most endangered species to survive. That fits with the passage, and thus (B) could be true, yet could be false.
(C) also provides a conditional statement:
Fragmented Forest Ecosystem Loses ANY Plant or Animal Species g Cannot Sustain Itself Long-Term |
The "any" is far too extreme: the passage tells us of the world's most endangered species not all species.
(D) also provides us with a conditional statement:
| Complete Forest (i.e., |
Compare this with the conditional statement provided in the final sentence:
| Fragmented Forest Maintains Full Complement of Plant and Animal Species g Regular Interventions |
Quite simply, (D) works this way: If A, then B. Thus, If NOT A, then NOT B. We know what a fragmented forest require to maintain its full complement, but this does not necessarily mean that a nonfragmented forest does not require intervention to maintain its full complement.
(E) discusses how many fragmented forests are currently being intervened in. The passage provides no information as to how many. It could be none, some, most, or all of the fragmented forests. Thus, no support exists for "some".
20. This LSAT argument is fairly straightforward:
| Premise: | Eating a lot of sugar produces a lot of adrenaline. |
| _________________________________________ | |
| Conclusion: | Eating a lot of sugar exacerbates ADD. |
Notice that the final sentence states "especially notable". This is essentially providing an example (not a premise), and you can ignore it. The assumption is that a lot of adrenaline exacerbates ADD, and thus choice (D) is the correct choice. The argument's structure works this way:
| Premise: | A (Eating a lot of sugar) produces B (a lot of adrenaline). |
| Assumption: | B exacerbates C (ADD) |
| _________________________________________ | |
| Conclusion: | A exacerbates C |
Yet, the difficulty with this LSAT assumption question is seeing the subtleties in the incorrect answer choices.
(A) refers to kids without ADD, which is irrelevant. This LSAT argument is concerned with kids who do have ADD.
The key word in (B) is "causes", whereas the argument states "exacerbates".
(C) refers to "most effective treatment", yet the author never mentions any type of treatment or the effectiveness of any treatments.
For choice (E), replace " is especially notable" in the final sentence with "only occurs". If this were the case, then we might consider (E), but it's not, so eliminate (E).
21. This is a somewhat rare occurrence on the LSAT -- the passage only contains claims, there are no premises. We must find a principle that helps justify the claims, i.e., find a choice that provides a principle that parallels at least one of the claims. The Ethicist makes three claims, which, we may place as conditional statements to better understand:
| Claim 1: | Avoid Alcohol Because Too Expensive g Should Not Be Praised |
| Claim 2: | Avoid Alcohol Simply Because Lack of Desire g Should Not Be Praised |
| Claim 3: | Praise Someone Who Avoids Alcohol Because Lack of Desire g Lack of Desire Resulted From Arduous Process |
The correct choice, (C), is a bit tricky because of the word "afford", which, in the context of (C) does not refer to "financial means" , but instead refers to an "arduous process".
(A) refers to "consequences" of behavior whereas the claims are concerned with the causes. Also, "social context" is not the Ethicist's concern; s/he is concerned with what takes place inside the individual.
(B) and (E) both contain "blame", which is irrelevant. The claims are concerned with praise, and the negation of praise is not praise, not "blame".
(D) refers to "acquiring self-discipline", whereas the final claim refers to using self-discipline to acquire a disinclination. Also, the "extent", or degree, is irrelevant. The Ethicist is not concerned with how arduous the process is, simply that the process is arduous.