Investigators have not proved that the forest fire was started by campers. Nor have they proved that lightning trigge...

shunhe on August 1, 2020

Hi @colleen_,

Thanks for the question! So first of all, what’s the exact flawed pattern of reasoning in the argument? Well, basically, we’ve potentially narrowed something down to two alternatives. But we can’t prove either one of them. So apparently, we can’t prove that it’s one of those two alternatives? That’s definitely not how things work, and that’s the error we want to replicate in the answer choice.

(A) tells us about Kim who doesn’t think Sada will win. And Kim doesn’t think Brown will win. So Kim shouldn’t think either of them will win. Well, that’s the exact same thing! There’s two alternatives, but we can’t be sure either one will win, so we can’t be sure that either one will win? Well, we know that one of them has to! So (A) parallels the reasoning and is the correct answer choice here.

(E), on the other hand, talks about a car that could’ve been driven by Jones or Katsarakis. So we know that the car could’ve been driven by them both. This isn’t flawed reasoning in the first place, and it doesn’t match up with the stimulus! We’re told in the stimulus “it’s not A, and it’s not B, so it’s not either of them,” whereas here, we’re told the opposite, “it could be A, and it could be B, so it could be either of them.” Since it’s backwards, (E)’s not right.

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