Logical reasoning PrepTest 157 · Section 2 · Question 19

If we diagrammed this claim, it would be "NOT upper-level → NOT prerequisite." This is an inaccurate version of the third premise. We know that if there are upper-level courses, then they will have prerequisites. However, that doesn't mean that upper-level courses are the only courses with prerequisites. Some lower-level courses could have prerequisites, too. The type of deduction this answer choice makes is often called an "inverse" flaw or an "illegal negation," and such deductions will always be wrong on Must Be True questions.

If we diagrammed this claim, it would be "All upper-level approved → Committee approved all courses." This is an inaccurate version of the second premise. It looks a bit like the "converse" flaw or "illegal reversal" of that premise. This answer choice also misconstrues the second premise's conditions since this answer choice is about approving all the courses rather than just approving one course.

And, if we compare this statement to the rest of the premises, we'll see that it's not necessarily true. The committee would not have to approve all the proposals for all the new courses to be upper-level. The committee could have rejected a few upper-level proposals it received, and Dean Wilson could have rejected all the proposals they received, and all the new courses would still be upper-level courses. For these reasons, we can eliminate (B).

This statement must be true. This statement is consistent with the following conclusion we drew:

Conclusion: Course approved → Prerequisite or Dean Wilson received

If there is more than one new course next year, then at least one of them will have a prerequisite. We know that Dean Wilson only received "one new course proposal." Even if that is a lower-level course without a prerequisite and Dean Wilson approves it, that would only represent one new course. If there's at least one other new course, its proposal would have been reviewed by the committee. The committee only reviewed upper-level courses with prerequisites, so that course would necessarily have a prerequisite. Since (C) is a demonstrably true statement based on these premises, we can select it and advance directly to the next question.

This is a very tempting answer choice! If it said that, "If the new course proposal that Dean Wilson received is for an upper-level course, then all new courses offered next year will have prerequisites," it would be accurate. That would mean that all the courses the committee and Dean Wilson reviewed and approved were upper-level, all with prerequisites.

However, (D) doesn't quite say that. It says, "If the new course proposal that Dean Wilson received is for an upper-level course, then all courses offered next year will have prerequisites." It doesn't specify that all *new* courses will have prerequisites. It describes all courses generally. And we don't know anything about preexisting courses. Many of them could be lower-level courses lacking prerequisites, making this answer a potentially false statement. What a difference one word makes!

This isn't necessarily true. If there are no new upper-level courses next year, that would mean that the committee rejected all of the proposals it received. But that doesn't mean that Dean Wilson would have had to accept the proposal they received. The Dean could have rejected that proposal, too. There's no stipulation that there has to be at least one new course this year.