Q21 - On the discount phoneline

[demetri.blaisdell]

Robowarren,

You're right: (C) has a conclusion mismatch. This is a quirky question because each answer choice starts with exactly the same two sentences, so you only have the conclusion to go on.

The stimulus concludes with: if it's not X, it's Y.

(A) doesn't even follow the internal logic of the answer choice. If there isn't extensive lab work, it should be in a normal classroom.

(B) is close, but it concludes that the conditions for the laboratory must exist (extensive lab work). We want a conclusion about where we are.

(C) gives us: if it is X, it isn't Y. Close, but not the way the stimulus works. The negation problem actually affects the logic. "If it's X, it's not Y" doesn't require that there only be X and Y. But if you say "if it's not X, it must be Y," you are saying that there are only two options. (C) only tells us that "Xs aren't Ys."

(D) is similar to (B). It basically restates the logical relationship between the condition (lab work) and the location (laboratory).

(E) is the winner. It compares location to location which matches the stimulus's comparison of price to price. If it's not X, it's Y. There are two places to conduct university classes. If you're not in a normal classroom, you're in the lab.

I hope this helps. Let me know if you have any further questions. I'd be happy to answer them.

Demetri

#officialexplanation

[robowarren]

Hi,

Could someone explain why C cannot be the answer? Is it because it employs a negative?

Thanks!

[s.tofighbakhsh]

In case this helps; I initially chose B, then went back and diagrammed it and changed my answer to E. My diagram looked like this:

9-5 --> 15c
~9-5 --> 10c
THUS, -10c --> 15c

So the set up of all the answer choices is:

extensive lab work --> lab
~extensive lab work --> normal

And the right answer HAS to say: THUS, ~normal --> lab

Logic was MUCH easier to match when it was laid out like math!