Among the various models of Delta vacuum cleaners, one cannot accurately predict how effectively a particular model c...

shunhe on October 2, 2020

Hi @Isabel-Zuniga,

Thanks for the question! So let’s take a look at the stimulus. We’re told that among the various Delta vacuum cleaner models, one can’t accurately predict how effectively one cleans by looking at how powerful the motor is. The efficiency of dust filtration systems varies significantly, even between different models with the same-power motors.

So now we’re asked for something that allows the conclusion to be properly drawn. In other words, this is a strengthen with sufficient premise question. First of all, what’s the conclusion we’re trying to properly draw? It’s that one can’t accurately predict how effectively a model cleans based on how powerful its motor is. And what do we have right now? Well, we know something about the efficiency of dust filtration system varying. So what would make sense? It seems like we need to link dust filtration system efficiency with effectiveness of cleaning.

Now take a look at (A), which tells us that the efficiency of dust filtration systems has a significant impact on how effectively a model cleans. Well, if we add that to the stimulus, then we can definitely get to the conclusion! So (A) is what we need and is the correct answer.

(B), on the other hand, tells us that one can accurately infer how powerful a DVC’s motor is from the efficiency of the vacuum cleaner’s dust filtration system. But this doesn’t mention the effectiveness of cleaning, and that’s the conclusion we need! So (B) can’t be the correct answer here.

Hope this helps! Feel free to ask any other questions that you might have.