Critical Reasoning

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%.

This is one big ol' trick question.

Maybe the key thing to notice is that the award goes to the town that has most increased the area of its green space in the past 12 months, but nothing in the prompt either tells us either the relative areas of the towns or gives us a way to calculate the green space that either will be adding.

The only numbers we are given are the percentage of each town's space that is already designated green space.

So something that would justify the officials' confidence has to include some kind of way of determining which town will actually be increasing its green space by a greater amount.

Here is a key thing to consider too. Often people doing CR questions don't bother to figure out exactly what is going on. Instead they either seek to use some general elimination strategy like "Avoid extremes." or they kind of pick an answer that "seems right" to them. This question with its multiple trap answers each of which might "seem right" is a great example of why you are better off figuring out exactly what is going on in CR questions and answer choices.

A) This gives the percentage increase for each town, but we don't know the relative or actual sizes of the towns. So we can't determine which will be actually increasing its green space by a greater amount.

B) This is too funny, because it basically gives the answer, saying essentially that Arlington's additional green space will be less than Barrington's additional green space. The 80% part makes this answer choice look like the other answer choices, and one might be tempted to somehow combine this answer choice's numerical information with the numerical information in the prompt. The truth is, however, that this answer choice on its own provides just the information we need.

C) Here's a trap answer. We have the current percentage of space that's green for each town, and this answer choice shows how much each town will increase green space relative to what it already has. So one might be tempted to think that combining this choice with the information in the prompt is a way to get to the answer, but actually from this answer choice we don't get any way to compare the areas of the towns or the amounts of green space they will be adding.

D) Here's another trap answer. You might think that by combining what's said here with what is said in the prompt you can get a way to compare the added green spaces of the town, but once again that's not the case.

E) This is another trap answer that once again seems to provide the information needed without actually doing that.

So the right answer is B.

Marty Murray wrote:This is one big ol' trick question.

Maybe the key thing to notice is that the award goes to the town that has most increased the area of its green space in the past 12 months, but nothing in the prompt either tells us either the relative areas of the towns or gives us a way to calculate the green space that either will be adding.

The only numbers we are given are the percentage of each town's space that is already designated green space.

So something that would justify the officials' confidence has to include some kind of way of determining which town will actually be increasing its green space by a greater amount.

Here is a key thing to consider too. Often people doing CR questions don't bother to figure out exactly what is going on. Instead they either seek to use some general elimination strategy like "Avoid extremes." or they kind of pick an answer that "seems right" to them. This question with its multiple trap answers each of which might "seem right" is a great example of why you are better off figuring out exactly what is going on in CR questions and answer choices.

A) This gives the percentage increase for each town, but we don't know the relative or actual sizes of the towns. So we can't determine which will be actually increasing its green space by a greater amount.

B) This is too funny, because it basically gives the answer, saying essentially that Arlington's additional green space will be less than Barrington's additional green space. The 80% part makes this answer choice look like the other answer choices, and one might be tempted to somehow combine this answer choice's numerical information with the numerical information in the prompt. The truth is, however, that this answer choice on its own provides just the information we need.

C) Here's a trap answer. We have the current percentage of space that's green for each town, and this answer choice shows how much each town will increase green space relative to what it already has. So one might be tempted to think that combining this choice with the information in the prompt is a way to get to the answer, but actually from this answer choice we don't get any way to compare the areas of the towns or the amounts of green space they will be adding.

D) Here's another trap answer. You might think that by combining what's said here with what is said in the prompt you can get a way to compare the added green spaces of the town, but once again that's not the case.

E) This is another trap answer that once again seems to provide the information needed without actually doing that.

So the right answer is B.

Thanks for your explanation marty.
But this question still scares me and appears to be very confusing.
Can u explain the same with an example or figures(Probably.)

Mechmeera wrote:Can u explain the same with an example or figures(Probably.)

The prompt says that the town that most increases its green space will receive the award. So we need a way to determine which town increase its green space the most.

Notice, it does not say that the award will be given to the town that increases its green space by the greatest percentage, but rather simply that the award will be given to the town with the greatest increase in space. While this way of choosing may not sound fair, it is the rule we are given.

We are given the methods the towns plan to use and their current green space percentages. Now we need a way to determine which town will see a greater actual increase in green space.

There is another quirk to this question as well. If we could combine the information given in multiple answer choices, we could figure out which town would receive the award. That can be confusing, because one can read one answer choice, and then when reading another one can get the impression that somehow there is sufficient information when actually that choice itself does not provide it.

A) We need to compare the changes in actual green space.

In order to use the percentages given in this choice we could seek to get from percentage to actual. However, while we know, for instance, that Barrington will increase its green space by 30%, we don't know what actual amount 30% represents because we don't know what the current green space is.

Alternatively, if we had some comparison of the areas of the green spaces of the two towns or of the total areas of the two towns, this choice would work.

If we were to know the current green space of Barrington to be twice the current green space of Arlington, for instance, we would not need the actual areas. We could just do the following.

.30 x 2a > .15 x a

If we were to know the total area of Barrington to be twice that of Arlington we could do the following.

.30 x .45 x 2a > .15 x .55 x a

We don't have the relative areas of the towns or their current green spaces though. So we can't do either.

B) This is it. All we need to know is the increase in area of green space. This says the following.

(Change In Arlington Green Space) < .80(Change In Barrington Green Space)

That also means the following.

(Change In Arlington Green Space) < (Change In Barrington Green Space)

The award is given on the basis of the change in green space. Given the information in this answer choice, we can see that Barrington's green space is going to change more and so Barrington will receive the award.

C) This is like A. We don't know the areas of the existing green spaces or of the towns. So merely having the percentage changes in green space is not enough to for us to get to the answer.

D) This is tempting, but insufficient. Area Arlington <= Area Barrington. Great, but all we have is the ability to determine the maximum possible difference between the area of the CURRENT green space in Arlington and that in Barrington.

Area Arlington <= Area Barrington

If the areas were equal then it would be the case that a = a and .55(a) > .45(a). That's the maximum by which the green space currently in Arlington could exceed that in Barrington.

D could be useful if we could combine its information with the information in A, because the information in D is the type of information, some indication of the relative areas of the towns, that we lacked in A. However, we can't combine the information from the two choices. So we have no way to compare the changes in green space.

E) This give us the following.

Arlington goes from .55(Area Arlington) to .60(Area Arlington).

Barrington goes from .45(Area Barrington) to .65(Area Barrington)

What's the problem? We don't know the areas or the relative areas. So these figures are useless for comparing the changes.

It could be that (Area Barrington) = .1(Area Arlington)

In that case we get the following.

(.65 - .45).1 < (.60 - .55)

Alternatively is could be that (Area Barrington) = 2(Area Arlington)

(.65 - .45)2 > (.60 - .55)

So with the information in the prompt combined with that given in choice E we can't determine which will have the greater increase in green space.

So the only choice that provides sufficient information is B.