Critical Reasoning

Source: Veritas

Each year, Carroll County gives an award to the town that has most increased the area of its green space in the past 12 months. To earn the zoning designation "green space," a lot must produce less carbon than it absorbs. Examples of land that qualifies as green space include parks, cemeteries, office buildings with highly efficient cooling systems, and homes with large gardens. 55% of the town of Arlington is designated as green space, while 45% of Barrington is designated as green space. Arlington officials have passed an ordinance declaring that any new office buildings built in Arlington in the next 12 months must have highly efficient cooling systems. Barrington officials have responded with a plan to open several new parks in the next 12 months. Barrington officials are confident that they will be ranked ahead of Arlington in the competition for the Carroll County award.

Which of the following, if true, would most justify the officials' confidence that Barrington will beat Arlington in the award rankings?

A. Barrington's new parks will increase its green space by 30%, while Arlington's new office buildings will increase its green space by only 15%.

B. Arlington's additional green space will not exceed 80% of Barrington's additional green space.

C. Arlington's new office buildings will constitute 10% of its existing green space, while Barrington's new parks will constitute 20% of its existing green space.

D. The area of Arlington is no larger than that of Barrington.

E. Barrington's new parks will bring its percentage of green space to 65%, while Arlington's new office buildings will bring its percentage of green space to only 60%.

Could anybody please solve this question and explain it.

eitijan wrote:Source: Veritas

Each year, Carroll County gives an award to the town that has most increased the area of its green space in the past 12 months. To earn the zoning designation "green space," a lot must produce less carbon than it absorbs. Examples of land that qualifies as green space include parks, cemeteries, office buildings with highly efficient cooling systems, and homes with large gardens. 55% of the town of Arlington is designated as green space, while 45% of Barrington is designated as green space. Arlington officials have passed an ordinance declaring that any new office buildings built in Arlington in the next 12 months must have highly efficient cooling systems. Barrington officials have responded with a plan to open several new parks in the next 12 months. Barrington officials are confident that they will be ranked ahead of Arlington in the competition for the Carroll County award.

Which of the following, if true, would most justify the officials' confidence that Barrington will beat Arlington in the award rankings?

A. Barrington's new parks will increase its green space by 30%, while Arlington's new office buildings will increase its green space by only 15%.

B. Arlington's additional green space will not exceed 80% of Barrington's additional green space.

C. Arlington's new office buildings will constitute 10% of its existing green space, while Barrington's new parks will constitute 20% of its existing green space.

D. The area of Arlington is no larger than that of Barrington.

E. Barrington's new parks will bring its percentage of green space to 65%, while Arlington's new office buildings will bring its percentage of green space to only 60%.

Premise:
In Arlington, where current green space constitutes 55% of the total area, any new office buildings must have highly efficient cooling systems.
In Barrington, where current green space constitutes 45% of the total area, officials have responded with a plan to open several new parks in the next 12 months.
Conclusion:
Barrington officials are confident that they will be ranked ahead of Arlington in the competition for the Carroll County award -- an award given to the town that has most increased the area of its green space in the past 12 months.

The correct answer choice must STRENGTHEN the conclusion that Barrington will win the award.

D: The area of Arlington is no larger than that of Barrington.
Here, it's entirely possible that Arlington's increase in green space will be greater than Barrington's, WEAKENING the conclusion that Barrington will win the award.
Eliminate D.

Try to DISPROVE the remaining choices with an extreme case.
Let:
The total area of Arlington = 10000 square miles, implying that the current green space in Arlington = 55% of 1000 = 5500 square miles.
The total area of Barrington = 100 square miles, implying that the current green space in Barrington = 45% of 100 = 45 square miles.

A. Barrington's new parks will increase its green space by 30%, while Arlington's new office buildings will increase its green space by only 15%.
Increase in Barrington's green space = 30% of 45 = 13.5 square miles.
Increase in Arlington's green space = 15% of 5500 = 825 square miles.
Here, the increase in Arlington is greater, WEAKENING the conclusion that Barrington will will the award.
Eliminate A.

B: Arlington's additional green space will not exceed 80% of Barrington's additional green space.
Here, Arlington's increase is LESS THAN Barrington's, STRENGTHENING the conclusion that Barrington will win the award.
Hold onto B.

C. Arlington's new office buildings will constitute 10% of its existing green space, while Barrington's new parks will constitute 20% of its existing green space.
Increase in Arlington's green space = 10% of 5500 = 550 square miles.
Increase in Barrington's green space = 20% of 45 = 9 square miles.
Here, the increase in Arlington is greater, WEAKENING the conclusion that Barrington will will the award.
Eliminate C.

E: Barrington's new parks will bring its percentage of green space to 65%, while Arlington's new office buildings will bring its percentage of green space to only 60%.
Increase in Barrington's green space = (65% of 100) - (45% of 100) = 20% of 100 = 20 square miles.
Increase in Arlington's green space = (60% of 10000) - (55% of 10000) = 5% of 10000 = 500 square miles.
Here, the increase in Arlington is greater, WEAKENING the conclusion that Barrington will will the award.
Eliminate E.

The correct answer is B.

GMATGuruNY wrote:
Premise:
In Arlington, where current green space constitutes 55% of the total area, any new office buildings must have highly efficient cooling systems.
In Barrington, where current green space constitutes 45% of the total area, officials have responded with a plan to open several new parks in the next 12 months.
Conclusion:
Barrington officials are confident that they will be ranked ahead of Arlington in the competition for the Carroll County award -- an award given to the town that has most increased the area of its green space in the past 12 months.

The correct answer choice must STRENGTHEN the conclusion that Barrington will win the award.

D: The area of Arlington is no larger than that of Barrington.
Here, it's entirely possible that Arlington's increase in green space will be greater than Barrington's, WEAKENING the conclusion that Barrington will win the award.
Eliminate D.

Try to DISPROVE the remaining choices with an extreme case.
Let:
The total area of Arlington = 10000 square miles, implying that the current green space in Arlington = 55% of 1000 = 5500 square miles.
The total area of Barrington = 100 square miles, implying that the current green space in Barrington = 45% of 100 = 45 square miles.

A. Barrington's new parks will increase its green space by 30%, while Arlington's new office buildings will increase its green space by only 15%.
Increase in Barrington's green space = 30% of 45 = 13.5 square miles.
Increase in Arlington's green space = 15% of 5500 = 825 square miles.
Here, the increase in Arlington is greater, WEAKENING the conclusion that Barrington will will the award.
Eliminate A.

B: Arlington's additional green space will not exceed 80% of Barrington's additional green space.
Here, Arlington's increase is LESS THAN Barrington's, STRENGTHENING the conclusion that Barrington will win the award.
Hold onto B.

C. Arlington's new office buildings will constitute 10% of its existing green space, while Barrington's new parks will constitute 20% of its existing green space.
Increase in Arlington's green space = 10% of 5500 = 550 square miles.
Increase in Barrington's green space = 20% of 45 = 9 square miles.
Here, the increase in Arlington is greater, WEAKENING the conclusion that Barrington will will the award.
Eliminate C.

E: Barrington's new parks will bring its percentage of green space to 65%, while Arlington's new office buildings will bring its percentage of green space to only 60%.
Increase in Barrington's green space = (65% of 100) - (45% of 100) = 20% of 100 = 20 square miles.
Increase in Arlington's green space = (60% of 10000) - (55% of 10000) = 5% of 10000 = 500 square miles.
Here, the increase in Arlington is greater, WEAKENING the conclusion that Barrington will will the award.
Eliminate E.

The correct answer is B.

Hi Mitch,
I have a doubt. Is the city considered a winner because of the total area after increase? or the just the increase (without adding it to existing area ?

Mo2men wrote:Hi Mitch,
I have a doubt. Is the city considered a winner because of the total area after increase? or the just the increase (without adding it to existing area ?

For each town, the following difference is calculated:
(new total area of green space) - (old total area of green space).
The town with the greatest difference is given the award.