7. The LSAT provides two conditional statements followed by a conclusion. We can graph out this information:

	P1: Infected g Rotten
	P2: Inspected g  Infected
	A: Infected g Safe to Eat
	_______________________
	C: Inspected g  Safe to Eat

 

Notice the new information in the conclusion -- "Safe to Eat". The author assumes that if food is not infected, then it is safe to eat. We now need to go to the answer choices and find either "Infected g Safe to Eat", or its contrapositive, "Safe to Eat g Infected". We can graph out the choices, and find what we're looking for in Choice (E). The choices provide the following information:

 

	(A) Rotten g Safe to Eat
	(B) Rotten g Safe to Eat
	(C) Had Been Inspected g Would Have Been Safe to Eat
	(D) Infected g Safe to Eat
	(E) Infected g Safe to Eat

 

8. The LSAT provides an argument that contains a comparison assumption -- what's true for the price of soft drinks between the 1970s and 1990 is also true for the price of a phone call between the 1970s and 1990. To weaken this argument, weaken the comparison by showing that a difference exists in determining the price of soft drinks and that of phone calls, which is what choice (D) provides.

(A) provides a distinction that appeared in the 1970s, but we need to know about 1990.

(B) seems to strengthen the argument by stating that the prices of greater than half ("most") goods have doubled. If so, then why not include phone calls?

(C) also seems to support the argument by letting us know that governmental restrictions have not become tighter, and thus perhaps the price of a phone call could be doubled.

(E) does nothing to the argument. "more sophisticated" does not necessarily equal higher cost for the telephone companies. It's equally possible that "more sophisticated" equals lower cost for telephone companies.

 

9. The LSAT asks for a choice supported by the information in the passage.

The key words in (A) are "maximum" and "main". We know nothing about "maximum" populations, and have no idea whether food source is the "main" factor.

(B) is our correct choice. Notice the phrase "at least in part" -- we are able to support this. Compare "at least in part" to "main" in choice (A) -- this type of language use is a common subtle distinction between correct and incorrect choices.

(C) provides a conditional statement :

 

A small-animal species becomes extinct g At least one large-animal species becomes extinct

 

Or, we could rephrase (C) as: The extinction of a small-animal species in a given environment with deteriorating conditions requires that at least one large-animal species also becomes extinct. There is no requirement listed in the passage for the extinction of a small-animal species -- eliminate (C).

The key word in (D) is "primarily", which the passage does not support. Compare (D) with (B).

The key phrase in choice (E): "are able to find enough food". We know that large-animal species are "more vulnerable", but it's possible that both large-animal and small-animal species are unable to find sufficient food.