1. The LSAT's first question on this test requires you to weaken an argument that contains causality. The argument assumes that lying is the only cause for the reactions. To weaken the argument, find a choice that provides another possible cause for the reactions, which is found in (D).
(A) does nothing to the argument, which does not require that all or most physiological reactions be measured.
(B) states that people are unaware. If anything, this supports the argument because if they are unaware, then they apparently will not attempt to alter their physiological reactions to fool the test.
(C) compares lying about criminal behavior versus lying about other things. The argument is not concerned with what people are lying about, just whether they are lying.
(E) provides information about what causes people to lie, which is irrelevant. The argument is concerned with an effect (physiological reactions) of lying.
2. Be wary of the first sentence of this LSAT passage -- it is simply introductory information. The conclusion and premise appear in the second sentence:
P1: Book with Best Sales Prospects Unlikely to Sell 100,000
|C: Unlikely Company Will Sell 100,000 Books|
Notice that the author does not take the next step and conclude: "Thus, it is unlikely that the company will make a profit." Although this is an inference you may draw, the question asks about the error made within the reasoning, and so be wary of choices that refer to the inference, rather than the author's conclusion. This LSAT error question contains a part versus whole assumption: the Publishing executive assumes that what is true for a part (title with best sales prospects) is true for the whole (all twelve titles). Choice (D) accurately describes this error.
(A) is wrong because the executive addresses this possibility in the final line of the paragraph. Note: There is no numerical value implied with the word "considerably", as there is for words such as "some" and "most".
(B) does not address the executive's conclusion, but rather the first sentence and "profit".
(C) is too broad -- the argument's focus is on this year, not "overall profitability".
(E) refers to advertising, which is not part of the argument. The passage does not state how the titles are sold. Also, if the company sells even fewer books, then the author's conclusion still holds.
3. This LSAT support the argument question contains a sampling assumption: the author assumes that the study represents all instances of having a sixth sense of someone watching. Notice that the subjects are not independently stating: "I think that I am being watched." Instead, the subjects are asked a Yes/No question, and thus have a 50% chance of correctly answering by simply guessing. To support the argument, we seek a choice that supports the sampling assumption by showing that the study is not a fluke. Choice (C) does this by showing at least one more instance that the same subjects produced similar results in a similar situation.
(A) provides irrelevant information. It does not matter whether the subjects stated watched or not watched; instead, what matters is whether they answered correctly.
The final line in (B) makes the choice incorrect. If the experiment is over, then the researchers cannot influence subjects' choices.
The key word in (D) is "not". (D) weakens the argument because if the room was not soundproof, then perhaps the subjects simply heard noise outside the window, rather than relying upon a sixth sense.
(E) states who the subjects were, but this is irrelevant. The test is on a sixth sense, and educational level or study focus would have no effect on a sense.