Logical reasoning PrepTest 124 · Section 2 · Question 7

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
New technologies have saved billions of dollars per year in energy use, so they'll save over $200b 50—100 years from now.

Answer Anticipation:
This argument makes a prediction about the future. Whenever an argument makes a prediction about the future, there's a good chance that it's basing it on current or recent trends. When that happens, the argument assumes that those recent trends will continue.

That's the case here. Energy savings in buildings have saved billions, so they're projected to continue to do so into the future. However, things could change, resulting in the savings being lower or even nonexistent.

The argument assumes that these changes won't happen, so any answer that establishes the trend will continue into the future or rules out a change that would prevent that will serve as a correct answer here.

Answer Explanation:
This answer rules out one potential future change that would call the continuation of the trend into question, thus serving as a necessary assumption for the argument. If the energy—saving technology becomes prohibitively expensive in the future, then it won't be implemented, and thus the massive savings predicted won't come to pass.

Key Takeaway:
Projecting trends into the future is almost always questionable because things could change that change those trends. Whenever the LSAT is looking to the future, start to think about what could happen between now and then to throw that prediction off.

Incorrect. While another energy crisis might spur more investment into energy saving technologies, it's not the only thing that could cause that to happen, so it's not necessary for there to be another one for the prediction to come to pass.

Incorrect. If anything, buildings being less important would cut against the argument, and thus this answer wouldn't be a necessary assumption. That said, the relative importance of buildings is out of scope, as they could continue to see the same level of energy savings while becoming relatively less important because transportation increases in importance, not because buildings become less important overall.

Incorrect. This answer is definitely tempting! However, two issues. First, in tying itself to $200b, it's more specific than the conclusion about more than" $200b. Second, the conclusion notes that that number is calculated in "current dollars, and this answer doesn't have the same note. As such, we can eliminate this answer.

Incorrect. The conclusion is about energy savings from these efficiencies" will save over $200b/year in 50—100 years, so the argument doesn't rely on assuming there will be new technologies/efficiencies. This answer is out of scope.