18. (A)
Question Type: Unconditional (Orientation)
Orientation questions ask us to choose a complete and accurate arrangement of the elements (parking lots, in this case). Orientation questions often lead off the set of questions. They can be solved by working through the constraints one by one and eliminating any choice that violates the constraint. Start with the constraints, NOT the answer choices.
We’ll start with the first constraint which comes from the problem set up: Anastasia parks in each lot at least once during the week. Answer choice (D) violates this constraint. Eliminate it.
Next, Anastasia Parks in the $15 lot on Thursday. We know from our diagram that this means she cannot park in Z on Thursday. Answer choice (E) has Z on Thursday. Eliminate (E).
The next constraint tells us that Lot X costs more than Lot Z, and that constraint doesn’t help us alone on this question. But if we combine it with the next constraint: that the lot Anastasia uses on Wednesday costs more than the Friday lot, then we know that we could not possibly have both Lot Z on Wednesday and Lot X on Friday (because X>Z and W>F). Answer choice (B) violates this combined constraint, so eliminate it.
Finally, Anastasia parks in lot Z more times than lot X. Between answer choice (A) and (C), we must choose (A) because in answer choice (C), Lots Z and X are both used twice and this violates our final constraint.