LSAT 113 | Section 3 | Logical Reasoning: Q2

LR Question 2 Explanation

QUESTION TEXT: For the last three years, entomologists have been searching for a…

QUESTION TYPE: Necessary Assumption

CONCLUSION: The search for a parasite has been a wasted effort.

REASONING: The whitefly turns out to have been a silverleaf whitefly rather than a sweet potato whitefly.

ANALYSIS: The argument is assuming that whatever parasite they find won’t work on both types of whitefly.

___________

1. The conclusion is about the parasite, not the effects of the whitefly. Even if all sweet-potato whiteflies were pests the search may still have been a waste because the parasites would work against the silverleaf whitefly. 
2. The argument wasn’t claiming that a parasite would necessarily work. It argued that the search for a parasite had been in vain.
3. This answer choice talks about the future. The stimulus was saying that past effort had been wasted.
4. CORRECT. If some parasites can attack both types of whitefly then the search might not have been in vain. 
5. This isn’t necessary. The entomologists might have found a parasite but concluded that it wouldn’t work to control the pests.