The U.S. Department of Agriculture divides the North American continen

Question

The U.S. Department of Agriculture divides the North American continent into “hardiness zones.” These zones are based on the average winter temperature and are used to determine what types of plants will likely survive in a given area. Zone 1 represents the coldest average winter temperature and zone 13 the warmest. The zones are closely correlated with, but do not exactly match another set of eleven zones that indicate the length of the growing season. Minneapolis is in hardiness zone 4 and Denver is in hardiness zone 6.

Which of the following statements is most supported by the information above?

A. During the coming winter, the lowest recorded temperature in Minneapolis will be lower than the lowest recorded temperature in Denver.

B. The growing season in Denver is much longer than the growing season in Minneapolis.

C. A greater variety of plants can be grown in Denver, due to the warmer average winter low.

D. Factors other than average winter temperature affect the length of the growing season.

E. At least one U.S. city has a colder average winter temperature than does Minneapolis.

KarishmaB · Accepted Answer

Responding to a pm:
There is absolutely no ambiguity in this question.

Premises:
- Hardiness zones are based on the average winter temperature and are used to determine what types of plants will likely survive in a given area.
- Zone 1 represents the coldest average winter temperature and zone 13 the warmest. 
- The zones are correlated with, but do not exactly match another set of eleven zones that indicate the length of the growing season - probably colder means shorter growing season from common knowledge
- Minneapolis is in hardiness zone 4 and Denver is in hardiness zone 6.

A. During the coming winter, the lowest recorded temperature in Minneapolis will be lower than the lowest recorded temperature in Denver.
We only know about average temperatures, not lowest.

B. The growing season in Denver is much longer than the growing season in Minneapolis.
Hardiness zones do not match the eleven "length of growing season" zone.

C. A greater variety of plants can be grown in Denver, due to the warmer average winter low.
No information about whether more variety survives in warm climate or cold - we will not use our general knowledge.

D. Factors other than average winter temperature affect the length of the growing season.
It is given that zones are correlated but DO NOT match exactly. It means other factors also come into play. Correct answer.

E. At least one U.S. city has a colder average winter temperature than does Minneapolis.
If you feel that "city" vs "area/town/piece of land" is nitpicking, then that's not correct. Perhaps a small wild piece of land right next to Canada lies in the hardiness zones 1, 2 and 3. Perhaps only some forest/mountain region lies in the first 3 zones. Perhaps no city lies in these zones since a city invariably ends up being warmer than the wild due to industrial activity. We don't know. 
-  But more importantly,  North American continent includes not just US but also Canada and Mexico. Hence, even if you ignore the difference between city/town etc, nothing says that a US city must lie in first three zones. US and North America are not interchangeable!

aditya8062 · Answer

@ original poster : i am really doubting this question !! 
i do not find any reason to reject option E :  At least one U.S. city has a colder average winter temperature than does Minneapolis. 
can u please check the choices again

blizzArd · Answer

There is nothing that implies that the "zones" are cities. They are just areas.

aditya8062 · Answer

so Denver and Minneapolis are areas !! not cities ?? after all some area will definitely comprise some city

justbequiet · Answer

Just as 1 city can comprise multiple hardiness zones (particularly if the city is big enough).

stoneshwar · Answer

A) Passage talks about average temperatures, not lowest,  so can't be A.

B) Could be true, but it says close correlation not exact.  We'll leave it as a possible choice for now since it's vague.

C)  Nothing in the passage suggests this.

D) The fact that length growing season and average winter temperature both have SEPARATE zones which are not exactly the same indicates that these 2 are not determined by the same factors.  Strongest contender.

E) Minneapolis is 4, but passage  does not suggest any other CITY is less than 4 . Could be town, village, inland water body. First sentence says it's a division of the continent, not a division of urban agglomerations.

AmoyV · Answer

I am in the same boat as you are in. I chose E too and was in for a shock. The source is Veritas Question Bank.

aditya8062 · Answer

i will not be worried about this question as long as it is not official !! i do not think GMAC will ever get into the nitpicking of "area", "city" or "town" 
also if someone is putting a logic that "cities" can be large enough to comprise more that one zone then the same argument can be put on the other side of story !! i mean why should we favor one side of the argument?

also if cities such as "Minneapolis" and "Denver" can have just one "zone" then we can definitely have other cities with just one "zone" ,after all there are cities smaller than Minneapolis !! (honestly i don't even want to get into this side of argument)

KarishmaB · Answer

Every word matters! Small differences in meaning can change the whole question!

Nevernevergiveup · Answer

The U.S. Department of Agriculture divides the North American continent into “hardiness zones.”
These zones are based on the average winter temperature and are used to determine what types of plants will likely survive in a given area.
Zone 1 represents the coldest average winter temperature and zone 13 the warmest.
The zones are closely correlated with, but do not exactly match another set of eleven zones that indicate the length of the growing season.
Minneapolis is in hardiness zone 4 and Denver is in hardiness zone 6.

Which of the following statements is most supported by the information above?

A. During the coming winter, the lowest recorded temperature in Minneapolis will be lower than the lowest recorded temperature in Denver.............we can infer that avg winter temp is lower but not lowest. new info.

B. The growing season in Denver is much longer than the growing season in Minneapolis...............this is new info as we don't any info in argument regarding growing season.

C. A greater variety of plants can be grown in Denver, due to the warmer average winter low..............we can decide type of plant in area based on zone avg winter temp not greater or fewer variety of plants.

D. Factors other than average winter temperature affect the length of the growing season..............can be true keep it at bay.

E. At least one U.S. city has a colder average winter temperature than does Minneapolis.............this cannot be inferred as atleast one city has a colder avg temp than does Minneapolis as the zones are divided among whole North American continent.

Show Spoiler

I got confused between C and D and sellected c since I felt D is too generalized. :wink:

Mahmud6 · Answer

Woul you please explain a little bit about it? How other factors come to play?

KarishmaB · Answer

The argument gives you 
"The zones are closely correlated with, but do not exactly match another set of eleven zones that indicate the length of the growing season. "

If the only factor that affected the length of the growing season was average winter temp, then the zones of length of growing season would have exactly matched the zones of temperatures. But the question tells us that they do not exactly match. So other factors such as "topography" could be playing a role in deciding the length of the growing season.

GMATYoda · Answer

Veritas Prep Official Solution:

Correct Answer is D.

This question illustrates a crucial logical principle: in order to show that an answer choice is incorrect on a “must be true” question, you do not need to show that it is “certainly not true”. All you have to do is come up with one example (which is often quite difficult) in which the conclusion is not true. On inference questions, it is unlikely that you will pick a “must be false” answer when you are asked for something that “must be true”. However, it is entirely possible that you will pick something that is likely to be true but not guaranteed to be true.

In this question, most of the incorrect answers are likely but not guaranteed. It is quite likely that, as choice A states, Minneapolis will have a lower extreme temperature than will Denver. Similarly, it is likely true that Denver has a much longer growing season. But neither is necessarily true. Denver has a higher average temperature, but that could be a result of shorter, colder winters and a quicker jump back to spring. And regarding choice B, the zones "do not exactly match" the length of the growing season, and Denver or Minneapolis might be one of those exceptions. Nothing states that the hardiness zones are associated with variety so choice C can be eliminated because of this fact.

For the most difficult incorrect answer - choice E - it seems that there must be a colder city since Minneapolis is only a four on a one to thirteen scale. However this scale is not just for cities and it is for all of North America, not just the U.S. It could very well be that the coldest city is a 4 (Minneapolis!) and only other rural areas or place outside of the U.S. are given lower ratings. D, however, can be proven: if the zones are not identical, then there must be another factor that accounts for the difference between hardiness zone and length of the growing season.

ssen92 · Answer

I am confused about the OA. I understand that zones need not be cities, and hence option E is incorrect. However, how can we say that factors other than average winter temperature affect "length of growing season". What if the zones for "length of growing season" are exactly based on hardiness zone but three zones were clubbed together because there really isn't much difference between those zones in terms of length of growing season?

Could you clarify this point?

Could you clarify this point?

kanikaa9 · Answer

I was able to come to D via elimination but I was having a hard time understanding is it really correct because I couldn't properly understand the line - "The zones are closely correlated with, but do not exactly match another set of eleven zones that indicate the length of the growing season" . I asked AI to break it down. See the explanation below to why  D is correct

1. Identify the key subjects in the statement
- "The zones" → Refers to the hardiness zones (based on winter temperature).
- "Another set of eleven zones" → Refers to the growing season zones (based on how long plants can grow).

2. Analyze the phrase "closely correlated with, but do not exactly match"
- "Closely correlated with" → Suggests a relationship between the two types of zones. So, when one changes, the other tends to change as well.
- "Do not exactly match" → Means they are not identical. There are situations where they don’t perfectly align.

3. Infer why they don’t match exactly
- Hardiness zones are based on average winter temperature, which determines plant survival in cold conditions.
- Growing season zones are based on frost dates, which dictate how many days plants can actively grow.
- A location might have mild winters (putting it in a warmer hardiness zone) but a short growing season (putting it in a different growing season zone) due to early autumn frosts.
- Another place might have harsh winters (a colder hardiness zone) but a long growing season (a different growing season zone) due to late frosts.

Final inference:
The statement tells you that while winter temperature affects plant survival and growing season length, other factors (like frost timing) prevent the zones from being exactly the same.

By focusing on the meaning behind "correlated" and "do not exactly match," you can infer that these two types of zones measure different aspects of climate, leading to some differences between them.  (Credits: Co Pilot AI)

BinodBhai · Answer

Confused between D and E..

My take on why E is incorrect:
The U.S. Department of Agriculture divides the  North American continent  into “hardiness zones.”  Here NA continent is not just US, but whole US, Canada, Alaska etc

Minneapolis is  in  hardiness zone 4 and Denver is  in  hardiness zone 6.  So many cities, towns, forests, lake etc can be in this zone

That's why E is incorrect, because a city might not be in zone 2 and 3.. so we can't properly infer that this will be true.

So by elimination, D is correct

egmat · Answer

BinodBhai

I can see you're thinking critically about the answer choices - and your instinct about choice E is actually spot-on! Let me help clarify why D is definitively correct and validate your concerns about E.

Why Choice E Cannot Be Inferred:

The passage tells us Minneapolis is in Zone 4, and zones 1, 2 and 3 are colder 
 However, we  cannot  assume that any  U.S. city  exists in these colder zones 
 As you correctly noted, these colder zones could contain:

Only Canadian territories
  
 Uninhabited areas of Alaska
  
 Rural/wilderness areas without cities

The GMAT requires us to stick to what can be definitively proven, not what seems likely

Why Choice D is Definitively Correct:

The key is this crucial phrase in the passage:  "The zones are closely correlated with,  but do not exactly match  another set of eleven zones that indicate the length of the growing season."

Think about what this means:
 
 If average winter temperature was the  only  factor affecting growing season length, the zones would match  exactly  
 Since they  "do not exactly match,"  there must be other factors at play 
 This directly supports choice D: "Factors other than average winter temperature affect the length of the growing season"

The U.S. Department of Agriculture divides the North American continen

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The U.S. Department of Agriculture divides the North American continen

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