Logical reasoning PrepTest 156 · Section 4 · Question 16

When an Errors in Reasoning answer choice starts with "presumes," we should ask, "Does the author believe this, and would this strengthen the argument?"

In this case, we don't know whether the manager believes that "factors that are collectively sufficient for success are also individually necessary for success." The manager doesn't list any factors that are sufficient for — or would guarantee — success. The manager says that a loosely bound group that shares a common purpose will be more successful than a tightly bound group, but that doesn't mean a loosely bound group that shares a common purpose will definitely be successful. A group can be more successful than another group without being successful per se. So, we don't know whether the manager thinks some factors are both sufficient and necessary for success.

Since the manager doesn't necessarily believe this claim, we can cross it off.

This isn't an error in the manager's reasoning. The manager proposes putting together a team of people who prefer not to work in tightly knit groups. So, the manager's research — which addresses the relative success of loosely bound and tightly knit groups — is definitely relevant to the proposed plan.

When an Errors in Reasoning answer choice starts with "takes for granted," we should ask, "Does the author believe this, and would this strengthen the argument?"

In this case, the manager doesn't necessarily believe that flexible teams "always function significantly better than inflexible teams." The manager just says that the flexibility of loosely bound groups helps them function "better" than tightly knit groups. The manager doesn't say the loosely bound groups perform "significantly" better. Moreover, the manager only says that loosely bound groups perform better when the group shares a common purpose. So, the manager doesn't necessarily believe that flexible, loosely bound groups "always" perform better than less flexible groups.

So, since the manager doesn't necessarily believe this claim, we can cross it off.

Moreover, even ignoring that issue, this answer choice tries to deny the truth of one of the manager's premises. That's not a proper way to point out an error in one's reasoning. To point out an error in one's reasoning, you need to show why the conclusion may not be true even if the premises are true.

When an Errors in Reasoning answer choice begins "overlooks the possibility," we should ask, "Would this, if it were true, weaken the author's argument?"

This answer choice, if true, would definitely weaken the argument. This shows that the manager's proposed team — which is full of people who would prefer not to work in tightly knit groups — would have trouble committing to a common purpose. The manager establishes that loosely bound groups can function better than tightly knit groups if the loosely bound group commits to a common purpose. But if the loosely bound group can't commit to a common purpose, we don't know if it can outperform its tightly knit counterparts. Perhaps loosely bound groups without a common purpose can't function at all. So, this answer choice weakens the manager's conclusion that their proposed team is "bound to succeed."

Since this answer choice would weaken the author's argument, we can select (D) and advance to the following question.

This isn't an error in the manager's reasoning. The manager's goal is to put together a "successful marketing team." The goal that "must be held in common by the members of the marketing team" is that the team shares "a common purpose." The manager doesn't confuse these two goals. The first is the manager's ultimate goal, and the second is a goal that is sufficient to make the manager's team outperform tightly knit groups. Since the manager treats these as separate goals, this answer choice doesn't describe a flaw in the manager's reasoning.