Lesson: Conclusion/Inference Questions

Comment on Conclusion/Inference Questions

Brent,
Can you please provide your approach to this question?

https://gmatclub.com/forum/theater-critic-the-play-la-finestrina-now-at-central-106202.html

Hi Brent. I got a little confused about this question:
https://gmatclub.com/forum/g-the-group-of-works-exhibited-in-this-year-s-metropolitan-234536.html

Is it an assumption or a conclusion question?
gmat-admin's picture

Question link: https://gmatclub.com/forum/g-the-group-of-works-exhibited-in-this-year-s...

I'd say that it's more of a conclusion question.

Cheers,
Brent

Hi Brent. Sometimes I face this kind of argument: https: //gmatclub.com/forum/when-an-ordinary-piece-of-steel-is-put-under-pressure-the-steel-255377.html

It's an argument with an underline part at the end. It asks us to complete the argument. Is it a conslusion question? Everytime I come across such a question can I assume it is a conclusion question or it may be other question type?
gmat-admin's picture

Question link: https://gmatclub.com/forum/when-an-ordinary-piece-of-steel-is-put-under-...

This is a Conclusion question.

The last sentence starts with "Therefore, if a ....", so this is going to be the conclusion, but this sentence is abruptly stopped, and we're asked to complete the conclusion.

CR questions that end with "________" can be any question type.

For example, if the last sentence starts with "The lawyer's argument is flawed because _______", then we can see that this is a Flawed Argument question.

Likewise, if the last sentence starts with "The lawyer's argument is further supported on the grounds that _______", then we can see that this is a Strengthen The Argument question.

And so on.

So, it's up to the test-taker to determine (by context) what type of question it is.

Does that help?

Cheers,
Brent

Absolutely. Perfect. Thanks a lot!

Devlin.

Hi Brent,

Please refer Q : https://gmatclub.com/forum/although-most-smoking-related-illnesses-are-caused-by-inhaling-the-tar-190802.html

Will I be correct to infer that answer choice (C) would have been correct in case the last statement in the stimuli("Unfortunately.....") was removed? In other words is the last statement responsible for conclusion (A) rather than (C)?

Thanks & Regards,
Abhirup
gmat-admin's picture

Question link: https://gmatclub.com/forum/although-most-smoking-related-illnesses-are-c...

Yes, you are correct.
If we eliminate the last premise (Unfortunately....."), then answer choice C is great.

Cheers,
Brent

Hi Brent,

Could you please help me with an easy and lucid explanation to this Q : https://gmatclub.com/forum/lyme-disease-is-caused-by-a-bacterium-transmitted-to-people-by-deer-ti-215972.html

Is this an Inference Q?

Thanks & Regards,
Abhirup
gmat-admin's picture

Hi Abhirup,

Yes, this is an inference question.

Here's my solution: https://gmatclub.com/forum/lyme-disease-is-caused-by-a-bacterium-transmi...

https://gmatclub.com/forum/five-years-ago-mcdonald-s-made-a-big-mistake-by-selling-off-its-chipo-250275.html
please explain
gmat-admin's picture

Question link: https://gmatclub.com/forum/five-years-ago-mcdonald-s-made-a-big-mistake-...

This is another question that is not GMAT-worthy. Here, we're required to know the relationship between market cap and revenue. The GMAT does not expect test-takers to know this.

Manjot, are you out of Official GMAT questions? There are TONS on GMAT Club.

Cheers,
Brent

Hi Brent,

Need your help with this one. It is from OG 19

Theater Critic: The play La Finestrina, now at Central Theater, was written in Italy in the eighteenth century. The director claims that this production is as similar to the original production as is possible in a modern theater. Although the actor who plays Harlequin the clown gives a performance very reminiscent of the twentieth-century American comedian Groucho Marx, Marx's comic style was very much within the comic acting tradition that had begun in sixteenth-century Italy.

The considerations given best serve as part of an argument that

A. modern audiences would find it hard to tolerate certain characteristics of a historically accurate performance of an eighteenth-century play
B. Groucho Marx once performed the part of the character Harlequin in La Finestrina
C. in the United States the training of actors in the twentieth century is based on principles that do not differ radically from those that underlay the training of actors in eighteenth-century Italy
D. the performance of the actor who plays Harlequin in La Finestrina does not serve as evidence against the director's claim
E. the director of La Finestrina must have advised the actor who plays Harlequin to model his performance on comic performances of Groucho Marx
gmat-admin's picture

https://gmatclub.com/forum/it-is-difficult-to-grow-cacti-in-a-humid-climate-it-is-difficult-to-r-287187.html
please explain i selected c
gmat-admin's picture

Question link: https://gmatclub.com/forum/it-is-difficult-to-grow-cacti-in-a-humid-clim...

Tricky question.

The main clue here is the word MOST, as in "In MOST parts of a certain country, it is either easy to grow cacti or easy to raise orange trees."

MOST = MORE THAN 50%

So, we can reword this as: In MORE THAN 50% of the country, it is either easy to grow cacti or easy to raise orange trees.
If it's easy to grow cacti in a region, then that region must NOT be humid.
If it's easy to raise orange trees in a region, then that region must NOT be cold.

In other words, In MORE THAN 50% of the country, it is NEITHER humid NOR cold.
This means that, in LESS THAN 50% of the country, the climate is some kind of mixture of humid and cold.

(A) Half of the country is both humid and cold.
This contradicts the conclusion that in LESS THAN 50% of the country, the climate is some kind of mixture of humid and cold.

(C) SOME parts of the country are neither cold nor humid.
We already concluded that "In MORE THAN 50% of the country, it is NEITHER humid NOR cold."
Since SOME = at least 1, answer choice C is possible.

Answer: A

Does that help?

Cheers,
Brent

https://gmatclub.com/forum/essayist-common-sense-which-is-always-progressing-is-nothing-but-a-287189.html
please explain
gmat-admin's picture

Question link: https://gmatclub.com/forum/essayist-common-sense-which-is-always-progres...

The essayist tells us that common sense ALWAYS contains some obsolete theories.

QUESTION: If all of the essayist’s statements are true, then which one of the following must be true?

(E) At least some theories that have been tested over time and found useful are less useful than some other theories that have not been fully absorbed into the body of common sense.
Since we're told that common sense ALWAYS contains some obsolete theories, we can be certain that common sense contains at least 1 obsolete theory (that has not yet been replaced)

Answer: E

Cheers,
Bret

https://gmatclub.com/forum/editor-y-this-is-a-good-photograph-the-composition-is-attractive-es-289562.html
sir confused b/w option c and d please explain
gmat-admin's picture

https://gmatclub.com/forum/the-fewer-restrictions-there-are-on-the-advertising-of-legal-services-151118.html

For this question, it says which of the following MUST be true,

But the correct answer ((C) If the restriction against advertisements that do not specify fee arrangements is removed, more lawyers will advertise their services.)
gives a definite conclusion ('WILL advertise their services'). Isn't this just a hypothesis? How can they say that if the restriction is removed, the lawyers WILL advertise their services? The passage doesn't state this ('The fewer restrictions there are on the advertising of legal services, the more lawyers there are who advertise their services, and the lawyers who advertise a specific service usually charge less for that service than lawyers who do not advertise')
gmat-admin's picture

Question link: https://gmatclub.com/forum/the-fewer-restrictions-there-are-on-the-adver...

The first sentence tells us that "The fewer restrictions there are on the advertising of legal services, the more lawyers there are who advertise their services."

In other words, "Fewer advertising restrictions CAUSES more lawyers to advertise"

In other words, "If there are fewer advertising restrictions, more lawyers WILL advertise"

Answer choice C is just a rewording of this premise. It says that, if the remove one certain advertising restriction (i.e., ads specifying fee arrangements), then more lawyers will advertise their services.

Does that help?

Cheers,
Brent

Hi Brent,

Could you please explain why it is guaranteed that "During the past 3 days, at least one Florida orange farm has experienced temperatures lower than 40 degrees Celsius. ", we only know that the temperature has not exceeded -5. It doesn't imply that the temperature went below a specific point. Maybe the minimum was -15. How do you know that for sure that there must be at least one farm that experienced such a low temperature.
gmat-admin's picture

I think you may be confusing "40 degrees Celsius" with "-40 degrees Celsius".
If the temperature never exceeded -5, then the temperatures COULD have been -5, -6, -7, -8, -9 -10, .....

-5 is quite cold (it's below freezing). So, the premise tells us that EVERY orange farm is experiencing very cold (below freezing) temperatures.

On the other hand, 40 degrees Celsius is very hot.

So, we can be certain that EVERY orange farm has experienced temperatures lower than 40.

So, the following statement MUST be true: During the past 3 days, AT LEAST ONE Florida orange farm has experienced temperatures lower than 40

i.e., if EVERY orange farm experienced temperatures lower than 40, then we can be certain that AT LEAST ONE farm experienced temperatures lower than 40.

Does that help?

Cheers,
Brent

when you say "lower than 40" = "lower than +40", but I assume you mean "-40", otherwise it is an incorrect assumption
gmat-admin's picture

I mean lower than +40 degrees.

Here's an analogous question.
Each of the 40 dogs at the dog park weighs more than 100 pounds. Which of the following statements must be true?
(A) At least one of the dogs at the dog park weighs more than 1 pound.
.
.
.

Since answer choice A is guaranteed, it must be the correct answer.

Does that help?

Hi Brent, Could you please explain, how D is correct for the following question ?

Theater Critic: The play La Finestrina, now at Central Theater, was written in Italy in the eighteenth century. The director claims that this production is as similar to the original production as is possible in a modern theater. Although the actor who plays Harlequin the clown gives a performance very reminiscent of the twentieth-century American comedian Groucho Marx, Marx’s comic style was very much within the comic acting tradition that had begun in sixteenth-century Italy.

The considerations given best serve as part of an argument that

(A) modern audiences would find it hard to tolerate certain characteristics of a historically accurate performance of an eighteenth-century play

(B) Groucho Marx once performed the part of the character Harlequin in La Finestrina

(C) in the United States the training of actors in the twentieth century is based on principles that do not differ radically from those that underlay the training of actors in eighteenth-century Italy

(D) the performance of the actor who plays Harlequin in La Finestrina does not serve as evidence against the director’s claim

(E) the director of La Finestrina must have advised the actor who plays Harlequin to model his performance on comic performances of Groucho Marx

https://gmatclub.com/forum/in-the-course-of-her-researches-a-historian-recently-found-two-docume-113009.html

Hi Brent,

For correct answer C

How can we assume when the statement was written. It could be 100 years after he has been arrested, he comes out clean.

Thanks,
Erik
gmat-admin's picture

Question link: https://gmatclub.com/forum/in-the-course-of-her-researches-a-historian-r...

In the course of her researches, a historian recently found two documents mentioning the same person, Erich Schnitzler. One, dated May 3, 1739, is a record of Schnitzler’s arrest for peddling without a license. The second, undated, is a statement by Schnitzler asserting that he has been peddling off and on for 20 years.

The facts above best support which of the following conclusions?

(C) The undated document was written before 1765.

FACT #1: Erich was caught peddling in 1739
FACT #2: In a statement, Erich admitted to peddling for 20 years.

There are two possible scenarios that satisfy the two facts above:

Scenario A: Erich provided the statement BEFORE 1739
In other words, at some point before 1739, Erich admitted to 20 years of pedaling. After that statement, Erich was caught pedaling in 1739.
This scenario definitely satisfies answer choice C.

Scenario B: Erich provided the statement AFTER 1739
If Erich made the statement in 1740, then we can assume that he started pedaling in 1720, and was later caught in 1739.
This satisfies answer choice C.

If Erich made the statement in 1750, then we can assume that he started pedaling in 1730, and was later caught in 1739.
This satisfies answer choice C.

If Erich made the statement in 1755, then we can assume that he started pedaling in 1735, and was later caught in 1739.
This satisfies answer choice C.

If Erich made the statement in 1765, then we can assume that he STARTED pedaling in 1745. This is a problem! If Erich started pedaling in 1745, then he couldn't have been caught pedaling 6 years earlier (in 1739).

So, it MUST be the case that Erich made the statement BEFORE 1765.

Does that help?

Thanks, Brent for the detailed reply. But my reservation is - That being arrested for peddling (without a license) doesn't mean you committed the crime. You were just essentially caught. And doesn't mean that you definitely committed the crime before the arrest.

For argument's sake, He could have been arrested, then released after 10 years, and then started peddling for 20 years.

This kind of thinking is something that I have picked up from Gmat itself :/ :p

Please help!
gmat-admin's picture

Ahhh, I see what you mean.
It comes down to whether (Erich was ARRESTED for peddling) = (Erich was ACTUALLY peddling)

"One is a record of Schnitzler’s arrest for peddling without a license."
I read this as saying Erich was arrested BECAUSE he was peddling without a license.
You're reading it as saying Erich was arrested for ALLEGEDLY peddling without a license. .

Of course, it's easy to work backwards from the official answer and conclude that the passage is specifically stating that Erich was definitely peddling without a license, but your interpretation could also work.

I think this is a "let's agree to disagree" (disagree with the test-makers that is) moment and move on to other questions.

Hi Brent,

Sorry for posting so many questions today. I was having some internet problems, so a lot of questions have bundled up.

https://gmatclub.com/forum/the-country-of-virodia-has-until-now-been-barely-self-sufficient-in-322546.html

I was unable to understand the meaning of the passage. If the post by LogicGuru1 is on-point. Then still option A seems wrong.

It is not necessary that the cost increased because the profit margins could not sustain them. Maybe the retail wanted to maintain their margins or then wanted to increase their margins. These details are unstated in the passage.

Thanks,
Erik
gmat-admin's picture

Question link: https://gmatclub.com/forum/the-country-of-virodia-has-until-now-been-bar...

Is your question pertaining to the linked question? The passage doesn't mention anything about retail profit margins.

My bad, This is the correct link: https://gmatclub.com/forum/to-protect-certain-fledgling-industries-the-government-of-country-z-b-12491.html#p1709107

I was unable to understand the meaning of the passage. If the post by LogicGuru1 is on-point. Then option A still seems wrong.

It is not necessary that the cost increased because the profit margins could not sustain them. Maybe the retail wanted to maintain their margins or then wanted to increase their margins. These details are unstated in the passage.
gmat-admin's picture

Question link: https://gmatclub.com/forum/to-protect-certain-fledgling-industries-the-g...

If we apply the modified version of the Negation Technique here we get:
(A) Profit margins in those industries WERE high enough to absorb the rise in costs.
This negated answer choice contradicts the premise that says the industries' ability to compete was sharply limited.

Does that help?

But how do we realise that this is a hidden assumption question?
gmat-admin's picture

I know LogicGuru1 suggested this is a hidden assumption question, but it's not really necessary to draw that conclusion in order to correctly answer the question (I never read it as an assumption question).

Keep in mind that we can use the Negation Technique for Assumption questions and for Conclusion questions.

Thank You

https://gmatclub.com/forum/half-of-metroburg-s-operating-budget-comes-from-a-payroll-tax-of-2-per-321884.html

Please let me understand how option E is correct. No where it is mentioned about public sector in passage.

I chose B as answer option.
gmat-admin's picture

Question link: https://gmatclub.com/forum/half-of-metroburg-s-operating-budget-comes-fr...

Half of Metroburg's operating budget comes from a payroll tax of 2 percent on salaries paid to people who work in the city. Recently a financial services company, one of Metroburg's largest private-sector employers, announced that it will be relocating just outside the city. All the company's employees, amounting to 1 percent of all people now employed in Metroburg, will be employed at the new location.

B) Although the company's relocation will have a negative effect on the city's tax revenue, the company's departure will not lead to any increase in the unemployment rate among city residents.
The language here is too strong. All we know is that a company is relocating somewhere outside the city.
It COULD be the case that several people in the city have jobs that provide services to this large company. Some examples include cleaning staff, caterers, delivery personnel, security, etc. Since it's conceivable that the relocation could cause these people to lose their jobs, it need not be true that "the company's departure WILL NOT lead to ANY increase in the unemployment rate among city residents"

E) The company's relocation will tend to increase the proportion of jobs in Metroburg that are in the public sector, unless it results in a contraction of the public-sector payroll.
All jobs are either in the private sector or the public sector.
We're told the financial services company that's relocating is one of Metroburg's largest private-sector employers. So, if all of these private-sector employees leave the city, the PROPORTION of public sector jobs in Metroburg will definitely increase (unless the relocation results in a contraction of the public-sector payroll)

Does that help?

can you pls elaborate on negation method by a simple and understandable example..I have never understood.
regards
gmat-admin's picture

The Negation Technique works best for Assumption questions, but it can still apply to Conclusion/Inference questions.
I explain the technique (starting at 3:35) in the following video: https://www.gmatprepnow.com/module/gmat-critical-reasoning/video/1139

Cheers,
Brent

Office Hours

On December 20, 2023, Brent will stop offering office hours. 

Change Playback Speed

You have the option of watching the videos at various speeds (25% faster, 50% faster, etc). To change the playback speed, click the settings icon on the right side of the video status bar.

Have a question about this video?

Post your question in the Comment section below, and a GMAT expert will answer it as fast as humanly possible.

Free “Question of the Day” emails!