Last visit was: 10 Jul 2025, 07:51 It is currently 10 Jul 2025, 07:51
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
avatar
kalrac
Joined: 09 Mar 2010
Last visit: 20 Jul 2014
Posts: 14
Own Kudos:
91
 [79]
Given Kudos: 17
Concentration: Technology, General Management
Schools: McCombs '14
Schools: McCombs '14
Posts: 14
Kudos: 91
 [79]
4
Kudos
Add Kudos
74
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 10 July 2025
Posts: 102,615
Own Kudos:
740,072
 [4]
Given Kudos: 98,167
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,615
Kudos: 740,072
 [4]
1
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
General Discussion
User avatar
shrouded1
User avatar
Retired Moderator
Joined: 02 Sep 2010
Last visit: 29 Apr 2018
Posts: 609
Own Kudos:
3,125
 [4]
Given Kudos: 25
Location: London
 Q51  V41
Products:
Posts: 609
Kudos: 3,125
 [4]
2
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
User avatar
onedayill
Joined: 25 Feb 2010
Last visit: 08 Mar 2017
Posts: 207
Own Kudos:
336
 [3]
Given Kudos: 10
Posts: 207
Kudos: 336
 [3]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
This is cause and effect type of question.
E shows that reverse is not possible.
Therefore, E is correct.
User avatar
adishail
Joined: 06 Jun 2009
Last visit: 06 Feb 2012
Posts: 217
Own Kudos:
161
 [2]
Location: USA
WE 1: Engineering
Posts: 217
Kudos: 161
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Irrelevant a) Delta-32 does not prevent a carrier from contracting any disease other than the Plague.
Irrelevant b) The Plague is not similar to other diseases caused by bacteria.
Again, irrelevant :roll: c)Delta-32 did not exist in its current form until the sixteenth century.
Again, irrelevant :roll: :roll: d)No one who tested positive for Delta-32 has ever contracted a disease caused by bacteria.
They assumed this to be true, else this would have been a side affect and not the reason to survive the plague. In order for Delta-32 to be the reason of surviving, it had to be present before the plague spread and was not a result of exposure to the bacteria e)The Plague does not cause genetic mutations such as Delta-32.
User avatar
ChrisLele
User avatar
Magoosh GMAT Instructor
Joined: 28 Nov 2011
Last visit: 27 Jul 2020
Posts: 295
Own Kudos:
4,738
 [3]
Given Kudos: 2
Expert
Expert reply
Posts: 295
Kudos: 4,738
 [3]
3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Fun question!

One good way to attack the question is by negating the assumption. If we do so with (E) we get:

Negated Answer Choice: The Plague causes genetic mutations such as Delta-32.

If the Plague indeed caused Delta-32 to occur, then the researches hypothesis totally falls apart: Delta-32 did not protect against the plague.

Answer choice (C) says that Delta-32 came into being around the 16th century, about the time of the Plague. Therefore, it could have conceivably conferred immunity on those who carried the gene.

Hope that helps :).
avatar
Dipankar6435
Joined: 27 Jan 2013
Last visit: 21 Dec 2017
Posts: 58
Own Kudos:
Given Kudos: 38
Status:Breaking my head!!
Location: India
Concentration: General Management, Operations
GMAT 1: 740 Q50 V40
GPA: 3.51
WE:Other (Transportation)
GMAT 1: 740 Q50 V40
Posts: 58
Kudos: 120
Kudos
Add Kudos
Bookmarks
Bookmark this Post
kalrac
Researchers studying the spread of the Black Plague in sixteenth-century England claim that certain people survived the epidemic because they carried a genetic mutation, known as Delta-32, that is known to prevent the bacteria that causes the Plague from overtaking the immune system. To support this hypothesis, the researchers tested the direct descendants of the residents of an English town where an unusually large proportion of people survived the Plague. More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times higher than that found in other locations.

The researchers' hypothesis is based on which of the following assumptions?
a) Delta-32 does not prevent a carrier from contracting any disease other than the Plague.
b) The Plague is not similar to other diseases caused by bacteria.
c)Delta-32 did not exist in its current form until the sixteenth century.
d)No one who tested positive for Delta-32 has ever contracted a disease caused by bacteria.
e)The Plague does not cause genetic mutations such as Delta-32.



Please post the answers with explanations.

Got this question on one of MGMAT CATs. Even after reviewing the problem and reading some posts regarding this I can still not convince myself that E can be the right answer. Here is my submission regarding it -
To support this hypothesis, the researchers tested the direct descendants of the residents of an English town where an unusually large proportion of people survived the Plague. More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times higher than that found in other locations.
As highlighted these two parts in the argument tell us two things
1. This town had an unusually large number of people who survived the Plague.
2. More than half of the descendants tested positive for DElta-32 in this town, a number three times as high as other locations
Now E says - The Plague does not cause genetic mutations such as Delta-32.
This cannot be assumed as per the argument. Had plague caused the mutations the proportion of people having Delta-32 would have been much higher in other locations where the plague was much more widespread than in this town which had fewer instances of plague.
In fact in this question I feel no answer is correct.
Can some experts enlighten me on this :shock:
User avatar
plumber250
Joined: 07 Nov 2012
Last visit: 21 Dec 2015
Posts: 220
Own Kudos:
951
 [1]
Given Kudos: 4
GMAT 1: 770 Q48 V48
GMAT 1: 770 Q48 V48
Posts: 220
Kudos: 951
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Dipankar6435
kalrac
Researchers studying the spread of the Black Plague in sixteenth-century England claim that certain people survived the epidemic because they carried a genetic mutation, known as Delta-32, that is known to prevent the bacteria that causes the Plague from overtaking the immune system. To support this hypothesis, the researchers tested the direct descendants of the residents of an English town where an unusually large proportion of people survived the Plague. More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times higher than that found in other locations.

The researchers' hypothesis is based on which of the following assumptions?
a) Delta-32 does not prevent a carrier from contracting any disease other than the Plague.
b) The Plague is not similar to other diseases caused by bacteria.
c)Delta-32 did not exist in its current form until the sixteenth century.
d)No one who tested positive for Delta-32 has ever contracted a disease caused by bacteria.
e)The Plague does not cause genetic mutations such as Delta-32.



Please post the answers with explanations.

Got this question on one of MGMAT CATs. Even after reviewing the problem and reading some posts regarding this I can still not convince myself that E can be the right answer. Here is my submission regarding it -
To support this hypothesis, the researchers tested the direct descendants of the residents of an English town where an unusually large proportion of people survived the Plague. More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times higher than that found in other locations.
As highlighted these two parts in the argument tell us two things
1. This town had an unusually large number of people who survived the Plague.
2. More than half of the descendants tested positive for DElta-32 in this town, a number three times as high as other locations
Now E says - The Plague does not cause genetic mutations such as Delta-32.
This cannot be assumed as per the argument. Had plague caused the mutations the proportion of people having Delta-32 would have been much higher in other locations where the plague was much more widespread than in this town which had fewer instances of plague.
In fact in this question I feel no answer is correct.
Can some experts enlighten me on this :shock:

Hi dipankar,

The key thing you need to think about is the difference between the number of people who contracted the plague and the number of people who survived it.

The question talks about people who survive it, whilst you talk about numb of people who contract it.

Re-look in this light and it should be clearer....
avatar
chshashankreddy
Joined: 13 Apr 2011
Last visit: 30 Mar 2016
Posts: 13
Own Kudos:
37
 [1]
Given Kudos: 7
GMAT 1: 690 Q50 V34
Posts: 13
Kudos: 37
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Researchers studying the spread of the Black Plague in sixteenth-century England claim that certain people survived the epidemic because they carried a genetic mutation, known as Delta-32, that is known to prevent the bacteria that causes the Plague from overtaking the immune system. To support this hypothesis, the researchers tested the direct descendants of the residents of an English town where an unusually large proportion of people survived the Plague. More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times higher than that found in other locations.

The researchers' hypothesis is based on which of the following assumptions?
a) Delta-32 does not prevent a carrier from contracting any disease other than the Plague.
b) The Plague is not similar to other diseases caused by bacteria.
c)Delta-32 did not exist in its current form until the sixteenth century.
d)No one who tested positive for Delta-32 has ever contracted a disease caused by bacteria.
e)The Plague does not cause genetic mutations such as Delta-32

Conclusion: People survived the plague because they carried a genetic mutation Delta 32.

Negating each option, E stands out to break the conclusion.

-E = The plague causes the genetic mutation such as Delta 32. If the plague itself causes the mutation than all the people effected by the plague will possess the mutation which is the explanation for the premise provided.

Hence E.
User avatar
AryamaDuttaSaikia
User avatar
Jamboree GMAT Instructor
Joined: 15 Jul 2015
Last visit: 06 Dec 2019
Posts: 252
Own Kudos:
688
 [1]
Given Kudos: 1
Status:GMAT Expert
Affiliations: Jamboree Education Pvt Ltd
Location: India
Posts: 252
Kudos: 688
 [1]
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
The argument states that the mutated Delta-32 gene acted as a defense against the bacteria causing Black Plague. The descendants tested from the English town where most of the people did not have the disease provides additional evidence to the above claim. The author assumes that the gene was already in the mutated form and the mutation could not have been a result of the disease. "E" rightly identifies the assumption. If "E" is reversed that is Plague caused the mutation then in the reversed form "E" attacks the conclusion.
avatar
DeepikaV
Joined: 19 Jan 2014
Last visit: 11 Dec 2021
Posts: 16
Own Kudos:
Given Kudos: 68
Location: India
GMAT 1: 690 Q50 V34
GMAT 1: 690 Q50 V34
Posts: 16
Kudos: 1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi,

please explain why D is wrong in detail.
User avatar
KarishmaB
Joined: 16 Oct 2010
Last visit: 10 Jul 2025
Posts: 16,101
Own Kudos:
74,242
 [1]
Given Kudos: 475
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 16,101
Kudos: 74,242
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
DeepikaV
Hi,

please explain why D is wrong in detail.

Premises:

Researchers claim that certain people survived the epidemic because they carried Delta-32 which prevents Plague.
They tested the direct descendants of the residents of an English town where an unusually large proportion of people survived the Plague.
More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times higher than that found in other locations.

What is the assumption? A missing necessary premise?

• No one who tested positive for Delta-32 has ever contracted a disease caused by bacteria.

We are not assuming that people carrying Delta-32 can get no bacterial infection. All that the argument says is that Delta-32 prevents plague. It may be ineffective against other bacteria. We don't need to assume its effectiveness against all bacteria for our argument to hold.

• The Plague does not cause genetic mutations such as Delta-32.

The higher proportion of Delta-32 in that town could be explained in two ways:
- They had Delta-32 and hence did not get plague. If more people had Delta-32, it means more people would have survived.
- Their system resisted plague and that led to the mutation. If more people resisted and survived, it would mean more mutation.

By concluding that first case must have taken place, we are assuming that second did not. So that is why (E) is an assumption.
User avatar
BillyZ
User avatar
Current Student
Joined: 14 Nov 2016
Last visit: 03 May 2025
Posts: 1,147
Own Kudos:
21,909
 [1]
Given Kudos: 926
Location: Malaysia
Concentration: General Management, Strategy
GMAT 1: 750 Q51 V40 (Online)
GPA: 3.53
Products:
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
kalrac
Researchers studying the spread of the Black Plague in sixteenth-century England claim that certain people survived the epidemic because they carried a genetic mutation, known as Delta-32, that is known to prevent the bacteria that causes the Plague from overtaking the immune system. To support this hypothesis, the researchers tested the direct descendants of the residents of an English town where an unusually large proportion of people survived the Plague. More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times higher than that found in other locations.

The researchers' hypothesis is based on which of the following assumptions?

(A) Delta-32 does not prevent a carrier from contracting any disease other than the Plague.

(B) The Plague is not similar to other diseases caused by bacteria.

(C) Delta-32 did not exist in its current form until the sixteenth century.

(D) No one who tested positive for Delta-32 has ever contracted a disease caused by bacteria.

(E) The Plague does not cause genetic mutations such as Delta-32.

Let’s review the two roles played by assumptions:

Supporter Assumption: These assumptions link together new or rogue elements in the stimulus or fill logical gaps in the argument.

Defender Assumption: These assumptions contain statements that eliminate ideas or assertions that would undermine the conclusion. In this sense, they “defend” the argument by showing that a possible source of attack has been eliminated.

Three Quirks of Assumption Question Answer Choices

Over the years, certain recurring traits have appeared in Assumption answer choices. Recognizing these quirks may help you eliminate wrong answers or more quickly identify the
correct answer at crunch time.

1. Watch for answers starting with the phrase “at least one” or “at least some.”

For some reason, when an Assumption answer choice starts with either of the above constructions the chances are unusually high that the answer will be correct. However, if you spot an answer with that construction, do not simply assume the answer is correct; instead, use the proper negation (“None”) and check the answer with the Assumption Negation Technique.

2. Avoid answers that claim an idea was the most important consideration for the author.

These answers typically use constructions such as “the primary purpose,” “the top priority,” or “the main factor.” In every Assumption question these answers have been wrong. And, unless, the author specifically discusses the prioritization of ideas in the stimulus, these answers will continue to be wrong because an author can always claim that the idea under discussion was very important but not necessarily the most important idea.

3. Watch for the use of “not” or negatives in assumption answer choices.

Because most students are conditioned to think of assumptions as positive connecting elements, the appearance of a negative in an Assumption answer choice often causes the answer to be classified a Loser. Do not rule out a negative answer choice just because you are used to seeing assumptions as a positive part of the argument. As we have seen with Defender answer choices, one role an assumption can play is to eliminate ideas that could attack the argument. To do so, Defender answer choices frequently contain negative terms such as “no,” “not,” and “never.” One benefit of this negative language is that Defender answer choices can usually be negated quite easily.

Assumptions and Causality

“When a GMAT speaker concludes that one occurrence caused another, that speaker also assumes that the stated cause is the only possible cause of the effect and that the stated cause will always produce the effect.”

Thus, because the author always assumes that the stated cause is the only cause, Assumption answer choices tend to work exactly like Strengthen answer choices in arguments with causal reasoning. The correct answer to an Assumption question will normally fit one of the following categories:

A. Eliminates an alternate cause for the stated effect

Because the author believes there is only one cause (the stated cause in the argument), the author assumes no other cause exists.

B. Shows that when the cause occurs, the effect occurs

Because the author believes that the cause always produces the effect, assumption answers will affirm this relationship.

C. Shows that when the cause does not occur, the effect does not occur

Using the reasoning in the previous point, the author will always assume that when the cause does not occur, the effect will not occur.

D. Eliminates the possibility that the stated relationship is reversed

Because the author believes that the cause-and-effect relationship is correctly stated, the author assumes that the relationship cannot be backwards (the claimed effect is actually the cause of the claimed cause).

E. Shows that the data used to make the causal statement are accurate, or eliminates possible problems with the data

If the data used to make a causal statement are in error, then the validity of the causal claim is in question. The author assumes that this cannot be the case and that the data are accurate.
avatar
JuccGMAT
Joined: 26 Nov 2020
Last visit: 11 Mar 2022
Posts: 3
Given Kudos: 23
Posts: 3
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Conclusion:-certain people survived the epidemic because they carried a genetic mutation

We are looking for the information that states that those certain people really carried that genetic mutation. In other words, there shouldn't be any other way from which this mutation developed.

Choice E is the prefect match.
User avatar
krndatta
Joined: 09 Feb 2020
Last visit: 17 Oct 2024
Posts: 383
Own Kudos:
Given Kudos: 433
Location: India
Posts: 383
Kudos: 43
Kudos
Add Kudos
Bookmarks
Bookmark this Post
KarishmaB Ma'am,

The negation of option E is "The plague causes the Delta-32 mutation" This weakens the conclusion that Delta-32 was responsible for preventing the spread of plague because the plague itself was causing the Delta-32 mutation.

Please evaluate my reasoning.
User avatar
KarishmaB
Joined: 16 Oct 2010
Last visit: 10 Jul 2025
Posts: 16,101
Own Kudos:
74,242
 [2]
Given Kudos: 475
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 16,101
Kudos: 74,242
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
krndatta
KarishmaB Ma'am,

The negation of option E is "The plague causes the Delta-32 mutation" This weakens the conclusion that Delta-32 was responsible for preventing the spread of plague because the plague itself was causing the Delta-32 mutation.

Please evaluate my reasoning.

Yes, you seem to have it right.
Though just to be sure, let me point out that because scientists found that unusually large number of survivors in a town correspond with unusually large number of people with Delta-32 mutation, they concluded that Delta-32 helped in fighting plague.
But what if Delta-32 was caused by plague. That could also explain the unusually large number of people with both. Then also a town with unusually large number of survivors (people who caught the plague but did not die) will have unusually large number of Delta-32 mutations.
Option (E) says that plague does not cause Delta-32. So it negates a possible alternative explanation for the situation. To conclude that Delta-32 helps fight plague, we are assuming that no other alternative explanation works (so we are assuming that Delta-32 was not caused by plague).
Hence (E) is correct.
User avatar
shvm_sin7
Joined: 24 May 2024
Last visit: 09 Jul 2025
Posts: 22
Own Kudos:
Given Kudos: 86
Posts: 22
Kudos: 3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I did not quite understand, the surrvivors wre technically 'not infected' because their immune system protected them. Therefore negating the argument (E) should not cause an problems acc to me
Bunuel
kalrac
Researchers studying the spread of the Black Plague in sixteenth-century England claim that certain people survived the epidemic because they carried a genetic mutation, known as Delta-32, that is known to prevent the bacteria that causes the Plague from overtaking the immune system. To support this hypothesis, the researchers tested the direct descendants of the residents of an English town where an unusually large proportion of people survived the Plague. More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times higher than that found in other locations.

The researchers' hypothesis is based on which of the following assumptions?

(A) Delta-32 does not prevent a carrier from contracting any disease other than the Plague.

(B) The Plague is not similar to other diseases caused by bacteria.

(C) Delta-32 did not exist in its current form until the sixteenth century.

(D) No one who tested positive for Delta-32 has ever contracted a disease caused by bacteria.

(E) The Plague does not cause genetic mutations such as Delta-32.


This question is part of the GMAT Club Critical Reasoning : Assumption" Revision Project.

OFFICIAL EXPLANATION



The researchers claim that Delta-32 prevents its carriers from contracting the Plague. They support this claim by noting that a strikingly large percentage of descendants of Plague survivors carry the mutation. We are asked to find an assumption underlying the claim.

(A) The argument is specific to the relationship between Delta-32 and resistance to the Plague. Other diseases are irrelevant.

(B) Again, the argument is specific to the relationship between Delta-32 and resistance to the Plague. Other diseases are irrelevant.

(C) Delta-32 may have existed in its current form before the sixteenth century and the merit of the argument would not change.

(D) The argument does not claim that Delta-32 prevents all bacteria-caused disease.

(E) CORRECT. The researchers claim that Delta-32 prevented its carriers from contracting the Plague on the basis of its presence in descendants of Plague survivors. But it is theoretically possible that these descendants carry the mutation Delta-32 because the Plague mutated the genes of their ancestors. In order to claim that the mutation prevented the Plague, we must assume that the Plague did not cause the mutation Delta-32.
Moderators:
GMAT Club Verbal Expert
7349 posts
GMAT Club Verbal Expert
235 posts