GMAT™ Official Guide 2020, Diagnostic Test, Critical Reasoning, Page 34, Question 80.Key points: The question follows a
strengthen-the-argument format. Look for any flaws to see what needs shoring up.
Breakdown:
1) The flip-side to the previous question, this straightforward question asks about what
supports the argument. To do that, we need to understand the argument being made.
2) The passage informs us that exhaust from idling tour buses is damaging “beautiful Renaissance buildings.” To address the problem, the city has designated parking for buses, an action that “accommodates a third of the tour buses.” The argument is that because of the new parking arrangement, the damage “from the buses’ exhaust will diminish significantly.” What would help
strengthen such an argument? Perhaps if we knew the buses that produced the most damaging exhaust (or the largest amount of it) were the ones using the dedicated spaces, that would help, or if the bus drivers were also no longer allowed to leave their vehicles idling. That is enough to get things going and turn to the answers.
Answers:
(A) automobile exhaust
is not a significant threatAnalysis: This does touch on the environmental burden that buses in particular pose to the Renaissance buildings; on the other hand, it ignores the fact that two-thirds of the buses have no designated parking spaces, meaning that the majority of the most problematic polluters have NOT been removed. That certainly diminishes the impact of what otherwise appears to be a reasonable answer. Yellow light.
(B) the buildings
are not threatened by other types of pollution
Analysis: This response introduces a consideration I had overlooked, namely that of other sources of pollution besides vehicles. As I said in the previous analysis, however, the fact that the new parking spaces accommodate just a third of the tour buses is problematic, and it is unclear what effect such a half measure (or less) will produce. This answer
does not address the main problem that lies with the buses. With that said, I would go back and change my read on choice (A) to match this one: red light.
(C)
Tour buses spend
less than one-quarter of the time… transporting passengersAnalysis: If, as the passage states, “idling produces as much exhaust as driving,” then whether the tour buses are moving or not, exhaust can be an issue. But then the numbers come in:
less than 25 percent of the time, the buses are shuttling people around, so
more than 75 percent of the time, they are not. What about idling? With the new parking accommodations, one-third of the tour buses are presumably parked, or not idling, when immobile. It may not be a perfect solution, but it is better than anything else we have encountered up to this point. Yellow light.
(D)
More tourists come… by tour busAnalysis: I should sound like a broken record by now: the problem of
exhaust from idling buses is not considered. Why would the passage go to such lengths to ensure that the reader understood the issue if it were not significant? Red light.
(E)
Some… buses that are unable to find parking drive aroundAnalysis: Driving, like idling, produces exhaust, so only the parked buses would not be contributing to the overall pollution. Furthermore, what are we to make of “some”? That presumably means that some
other buses that are unable to find parking do NOT drive around, which means that they idle. If the engine is on, the vehicle is doing harm. Red light.
Guessing: Choice (C) appears to be the best answer, despite being sub-optimal, in my mind. (A) is off-topic, focusing on another type of vehicle, while (D) distracts the reader with tourists. Among (B), (C), and (E), choice (E) hides behind a vague “some” and outright tells us that the buses “drive around,” which we know is comparable to idling, in terms of producing damaging exhaust. That leaves a 50/50 between (B) and (C), and only (C) sets restrictions on tour buses in particular. On these harder questions, if you had to put a finger on the subject of each answer and assess all of them from such a starting point, it might help you cut out some of the distractions. Look at what happens here, for instance:
(A) automobiles
(B) buildings
(C) buses
(D) tourists
(E) buses
From the time “buses” are mentioned in the first sentence of the passage, they remain the focus thereafter. It makes sense, then, that an argument that also stems from buses would need support in the form of--what else?--buses. Between (C) and (E), it is much easier to expose flaws in the latter.
Good luck with your studies.
- Andrew
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