Logical reasoning PrepTest 134 · Section 1 · Question 18

Incorrect. The conditional statements do establish that modeling software was required for the financial predicament to be resolved, but it doesn't establish that a particular software was required. It's possible that a competing modeling software would have worked to resolve the predicament, as well.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Engineers increased Bridge traffic flow capacity
not Invested in modeling software at Mayor's request → not Increase in rush-hour traffic flow
not Increase in rush-hour traffic flow → not Financial predicament resolved

Answer Anticipation:
This answer features a statement about what happened, followed by two conditional statements. While the latter has a clear indicator word ("if"), the first has a bit of a trickier diagram. "[H]ad the city not" is the same as saying, "If the city didn't . . . ", and so we can diagram it out.

With those two statements diagrammed, we can see that they share a term and can be chained together, giving us a new conditional (and its contrapositive):

not Modeling software → not Financial predicament resolved
Financial predicament resolved → Modeling software

Answer Explanation:
This answer matches our anticipation—the combined conditional chain (not Modeling software → not Financial predicament resolved)—so it's correct.

Key Takeaway:
If you read a Must Be True question and think it has only a single conditional statement, but it has a second statement that shares a term with it, look for a non-traditional conditional indicator word. Here, it would have been easy to miss the conditional nature of the second sentence, but, "had the city not," is the same as saying, "if the city didn't."

Incorrect. The stimulus only discusses increased rush-hour traffic flow. That leaves open the possibility that overall traffic flow was, on average, higher before.

Incorrect. While that modeling software was necessary for the increase in rush-hour traffic flow, there's no indication that the investment in the modeling software needed to be the highest priority to happen. It's possible that it could have been the second highest budgeting priority and still been a high enough priority for the town to adopt it.

Incorrect. The motive is out of scope of the outcome. Why the Mayor wanted to invest in the software doesn't determine what impact the software has on traffic.