12 Days of Christmas GMAT Competition - Day 1: Some city planners

(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution.

This strengthens the argument and not weakens it. If the urban sprawl increases vehicle emissions then reduction of it should reduced urban pollution. However, we have to weaken the argument.

(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption.

The relation of higher energy consumption and city being warmer is not given. Hence, this statement neither supports or weakens the argument.

(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures.

This is a correct weakener. If the green spaces reduce , the urban temperature increases. Hence building skyscrapers can have the opposite effect. Let's keep this.

(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas.

Out of scope as housing costs are not the contention of the argument.

(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs.

Out of scope as costs or anything related to pricing is not the contention of the argument.

IMO C

Conclusion:- with modern energy-efficient designs, skyscrapers can actually reduce overall urban temperatures by centralizing populations and reducing urban sprawl.
we are required to evaluate this argument

(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution. The author already has mentioned that the energy-efficient designs would reduce the urban sprawl hence this do not lead to any evaluation

(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption. we are not bothered by high energy consumption but by urban temprature

(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures.
this is a proof that the even with energy-efficient designs a high concentration of skyscrapers will lead to higher urban temperature, hence it weakens the argument
(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas. irrelevant

(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs.
Irrelevant

My logic is the following:

We need to weaken the advocates' argument. What is the argument? "Skyscrapers can actually reduce overall urban temperatures" - this is what we need to weaken. Let's move to the answer choices:

(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution => it actually strengthens somehow the argument of the advocates in terms that urban sprawl is a huge problem so if everything is implemented as the advocates mentioned in their argument, the skyscrapers will help to tackle an issue of the urban sprawl.

(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption => this one may sound a bit confusing but I eliminated it since it is concerned with high energy consumption while we are interested in overall urban temperatures.

(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures => this implies a different consequence of building skyscrapers - a decrease in green spaces that increases urban temperatures. So what it says is that the more skyscrapers we have - the higher the temperature is. So this option breaks the relationship established by the advocates ("Skyscrapers can actually reduce overall urban temperatures"). This is our answer.

(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas => it is concerned with the housing costs, not the urban temperatures.

(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs => it is concerned with the investments, not the urban temperatures.

advocates arguments with modern energy efficient designs skyscraper can reduce overall urban temp by centralising populations and reducing urban sprawl


(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution.
this actually supports the skyscrapers advocate's argument which says it reduces urban sprawl

(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption. even though it talks about energy consumption it does not weaken the arguement as much as option c

(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures.
this is best one .....more skyscrapers --> higher urban temp
(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas.
it talks about disrupting communities and housing cost not urban temp and urban sprawl

(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs.
The argument has nothing to do with economic feasibility

The most serious weakness to the skyscraper advocates' argument is:

C. In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures.

Here's why:

A: While increased vehicle emissions from urban sprawl are a problem, they don't directly address the specific claim about skyscraper-induced heat islands.
B: While energy inefficiency can negate the environmental benefits, it doesn't necessarily worsen the heat island effect, which is the crux of the argument.
D: Community disruption and housing cost increases are valid concerns, but they don't directly address the environmental impact of heat islands.
E: High initial costs can be a challenge, but it doesn't weaken the claim about temperature reduction if the long-term benefits are significant.
Option C directly contradicts the claim that skyscrapers can reduce overall urban temperatures. A decrease in green spaces is known to contribute to the urban heat island effect, undermining the advocates' argument that centralized populations in skyscrapers can mitigate the issue. This directly challenges the core benefit they propose.

Therefore, C is the most serious weakness to the skyscraper advocates' argument.

(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution.
Supports having skyscrapers because want to lower vehicle emissions

(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption.
This sounds weaken, but it's a trap, it's unclear if projected means MASSIVE improvement projected or just OK improvement projected. I kept this if I couldn't find a better option.

(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures.
This weakens because the area gets hotter than before. I don't know what the temp was before, but I do know it's hotter than it was earlier.

(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas.
Supports skyscrapers because urban housing prices increase so people want to move to the city or housing increases in the urban part so that reduces urban sprawl.

(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs.
Informative, the skyscraper advocate knows this and doesn't care.


Answer C

Advocates for skyscraper construction argue that, with modern energy-efficient designs, skyscrapers can actually reduce overall urban temperatures by centralizing populations and reducing urban sprawl.
Our goal is to weaken this argument.
(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution.
Incorrect - Opposite - As this strengthens the argument of Advocates for skyscraper construction.

(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption.
Incorrect - Irrelevant - as conclusion is reduction of temperatures, however, Answer Choice B is about energy consumption.
(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures.
Correct - This option attacks the advocates argument and shows that the increase in skyscrapers results in higher urban temperatures due to significant decrease in green spaces.
(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas.
Incorrect - Irrelevant to the advocates argument
(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs.
Incorrect - Irrelevant to the advocates argument
Answer C

The argument of city planner -" Construction of new skyscrapers in urban areas increases the "urban heat island" effect and make cities warmer. This increased temp. increases pollution and impact public health."

Counter argument given by advocates for Skyscrapper- "Skyscrapper construction with modern energy-efficient designs can reduce temp. by centralizing pollution and reducing urban sprawl."

Which of the following, if true, most seriously weakens the skyscraper advocates' argument?

(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution. ~ Skyscrapper advocates argument is not related to the vechile emission.

(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption. ~ This weaken the argument partially if the energy- efficient sky scrappers designs not perform as proposed, than it may lead to the increase in the higher tempratures. But the second part of this option mentions that it will result in higher energy consumption (and not increase in temperature) which is not the argument proposed by the Skyscrapper advocates.

(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures. ~ Correct, this essentially weakens the argument that if increase in concenteration of Skyscrapper results in reduction in the green space and contribute to higher urban temperatures, than their argument is flawed.

(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas. ~ Skyscrapper advocates argument is not related to the increase in the housing costs in the urban areas.

(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs. ~ Skyscrapper advocate argument does not mention the economical feasibility of such projects.

IMO Choice C.

Some city planners argue against the construction of new skyscrapers in urban areas, claiming that taller buildings increase the "urban heat island" effect, making cities warmer. They suggest that this increase in temperature exacerbates pollution and impacts public health. In response, advocates for skyscraper construction argue that, with modern energy-efficient designs, skyscrapers can actually reduce overall urban temperatures by centralizing populations and reducing urban sprawl.

Which of the following, if true, most seriously weakens the skyscraper advocates' argument?

(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution.

(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption.

(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures.

(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas.

(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs.


Solution: To find a weakner, we need to look for an alternate cause of increase in urban temperatures besides the inefficient energy designs of skyscrapers which the advocates fail to consider and proposed that the new energy efficient designs of skyscrapers will reduce the urban temperatures and urban sprawl by centralization of population.

(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution.
Explanation: Here Urban pollution is discussed which is irrelevant to the given argument. Pollution is the result of increased temperature which the advocates claim can be reduced via new energy efficient skyscrapers. NOT CORRECT


(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption.
Explanation: This reasoning may or may not cause the increase in temperature levels. Though high energy consumption can lead to the "urban heat island" effect which eventually causes the increase in temperature levels but this statement fails to provide a deterministic and proven fact in support of its claim. NOT CORRECT


(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures.
Explanation: This option provides an alternate cause for the increase in temperature levels which the advocates failed to consider and went on proposing the new energy efficient skyscrapers would solve the problem. This choice clearly mentions that the high concentration of skyscrapers cause significant decrease in green spaces which in turn causes higher urban temperatures. CORRECT

(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas.
Explanation: Here Housing costs is discussed which is irrelevant to the given argument. Out of Scope. NOT CORRECT


(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs.
Explanation: Here investment cost and economic feasibility are discussed which is irrelevant to the given argument. Out of Scope. NOT CORRECT

Hence Option C is the correct choice.

(A) Urban sprawl has been shown to contribute significantly to increased vehicle emissions, which are a major source of urban pollution.
Pollution is not the point of discussion but just discussed as an effect.

(B) Studies have demonstrated that the energy-efficient designs of new skyscrapers often fail to perform as well as projected, resulting in higher energy consumption.
Irrelevant

(C) In cities with a high concentration of skyscrapers, a significant decrease in green spaces has been observed, contributing to higher urban temperatures.
Correct. The reason for higher temperatures from skyscrapers is discussed here.

(D) The construction of skyscrapers frequently disrupts existing communities and leads to increased housing costs in urban areas.
Cost is irrelevant.

(E) Energy-efficient skyscrapers require a substantial initial investment, making them less economically feasible than traditional building designs.
Cost is irrelevant.

Option C