LSAT PrepTest 43 Section 2 Question 4 Explanation | Logical Reasoning

I didn't write the following blog post. It was already on the blog when I took over the URL. The following blog post may contain mistakes. -Steve

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This Logical Reasoning question is from the June 2004 LSAT.

As always with arguments, let's make a short chain of phrases (which can just be done by underlining a few key words, once you gain experience) to show how the argument works:

Some think 5 years of high temps mean a permanent change --> 10 years of high temps can be random and common

What's the implication here, which we can pre-phrase to save time and answer the question about what proposition the argument supports? It's something like "short term high temps can just be random, not a major, long-term change." The whole point of saying that it can be a random fluctuation is to contradict the opinion the argument brings up that says the 5-year trend is indicative of a broader trend. We see immediately that choice B fits the pre-phrase well, since it mentions how the 5-year change may not mean anything long-term. Let's go through the other choices quickly:

A) The opposite of what we want, since the argument contradicts this choice. The argument mentions a 5-year major change, with record temps yearly, but this choice is saying that those fluctuations only occur over 10-year periods, which cannot be well supported by the argument.

B) Correct.

C) The opposite of what we want, since the argument contradicts it, just like in A. The argument says that these 5-year changes are often random without long-term implications, but this choice is saying the opposite, that this 5-year change means a long-term change, which is wrong.

D) Outside of the scope of the argument. Read carefully, I cannot possibly stress this enough. This doesn't mean taking forever, but you need to know just what the argument says and does not say. The argument is saying that 10-year temp changes don't mean that there is a long-term change, not that there is no long term change, and that 10-year changes are the max, as this answer choice is saying. That is a somewhat fine but very important distinction here...you have to get this kind of thing right to have even a chance on the LSAT. On a test this tough, misreading stuff isn't an option, you margin for error is too small. Practice up!

E) Wrong and outside the scope for the same reason as D. The argument's saying that 5-10 year changes don't necessarily indicate long-term change, not there is no long term change over more than, say, 10 years.

Remember:

1) Make a phrase chain (by underlining key words, as you learn more and can work more quickly) .

2) Eliminate answer choices that are outside the scope or the opposite of what the question asks for. Remember that if the question asks for what the argument supports, the right answer choice can't be something that directly contradicts the argument! To know what contradicts the argument and what's out of scope, do it quickly, but be sure to READ CAREFULLY! Otherwise, you'll have made so many dumb mistakes that, when coupled with questions that you got wrong just because they were too hard, your score will be in the toilet. Seriously. Reading well is the key to much of the RC and LR.