Paleomycologists, scientists who study ancient forms of fungi

Question

Paleomycologists, scientists who study ancient forms of fungi, are invariably acquainted with the scholarly publications of all other paleomycologists. Professor Mansour is acquainted with the scholarly publications of Professor DeAngelis, who is a paleomycologist. Therefore, Professor Mansour must also be a paleomycologist.

The flawed pattern of reasoning in the argument above is most similar to that in which one of the following arguments?

(A) When a flight on Global Airlines is delayed, all connecting Global Airlines flights are also delayed so that the passengers can make their connections. Since Frieda’s connecting flight on Global was delayed, her first flight must have also been a delayed Global Airlines flight.

(B) Any time that one of Global Airlines’ local ticket agents misses a shift, the other agents on that shift need to work harder than usual. Since none of Global’s local ticket agents missed a shift last week, the airline’s local ticket agents did not have to work harder than usual last week.

(C) Any time the price of fuel decreases, Global Airlines’ expenses decrease and its income is unaffected. The price of fuel decreased several times last year. Therefore, Global Airlines must have made a profit last year.

(D) All employees of Global Airlines can participate in its retirement plan after they have been with the company a year or more. Gavin has been with Global Airlines for three years. We can therefore be sure that he participates in Global’s retirement plan.

(E) Whenever a competitor of Global Airlines reduces its fares, Global must follow suit or lose passengers. Global carried more passengers last year than it did the year before. Therefore, Global must have reduced its fares last year to match reductions in its competitors’ fares.

darkwasp03 · Answer

What is the problem with answer option D?

AndrewN · Answer

Hello,  darkwasp03 . I will confess to taking 2:50 to solve this question. I am much more familiar with the format of official GMAT™ questions than those that are kind of similar on the LSAT, so I treat the latter with extra caution. To answer your question, the problem with (D) is that it does not follow the same absolute line in the beginning that is subsequently taken as a premise.

Passage :  Paleomycologists... are  invariably  acquainted

Answer :  All employees...  can  participate

The passage presents an absolute connection—by virtue of being a paleomycologist, such a scientist  will  be familiar with the work of others in the field. The answer, on the other hand, presents a choice—each employee may or may not (i.e. can) participate in the company retirement plan. It is this key difference that dissuaded me from pursuing (D) any further. Meanwhile, choice (A) follows the same absolute logic presented in the passage. When a Global Airlines (GA) flight is delayed, all connecting GA flights  will  be delayed, and the premise and conclusion are reversed in similar fashion. That is, we are expecting to read that  because  Professor Mansour is a paleomycologist, he must be acquainted with the work of others in the field. Instead, we get that Professor M. must be a paleomycologist, a conclusion,  because  he is acquainted with the work of one. Likewise, (A) indicates that Frieda must have had a delayed initial GA flight, a conclusion, since her connecting flight was delayed. We should logically expect the arrow of causality to point in the other direction.

I hope that helps. Good luck with your studies.

- Andrew

UkrHurricane · Answer

Hi. I believe this may help.

We can break down the text in the problem to the following:
A - Paleomycologists.
B - acquinted with publications of all paleomycologists.
So If A, then B.

However, the conclusion in this problem is that if B, then A, which may or may not be true (because there may be a number of other reasons that led to B) and is the flaw in the reasoning.

In answer choice D, the logic is as follows:
A - an employee of GA for 1 year+
B - CAN participate in retirement plan.
C - DOES participate in retirement plan.
So if A, then B.
However, the conclusion here is that If A, then C, a completely different flawed logic.

Hope this helps.

nikitamaheshwari · Answer

whats wrong with ans choice B?  GMATNinja

Pranjal3107 · Answer

Can someone explain how to approach such questions ? 
I did mark A but I was caught in two minds between A and E.

svasan05 · Answer

Pre-thinking:

This is a simple causality question, and we can use our knowledge of X --> Y (X leads to Y) structure to solve the problem.

Paleomycologists (X) --> acquainted with the scholarly publications of all other paleomycologists (Y)
Professor Mansour is acquainted with the scholarly publications of Professor DeAngelis, who is a paleomycologist (partly Y, because it doesn't say he is acquainted with  all  paleomycologists' publications) --> Professor Mansour must also be a paleomycologist (X)

Now, we know that when X --> Y, then Y (in this case it is not even Y fully, but let us go with Y) --> X need to be true. It is only true that Not (Y) --> Not (X). The flawed reasoning in this stimulus is:

X --> Y, therefore, Y (partly) --> X.

Let us examine the answer options:

(A) When a flight on Global Airlines is delayed, all connecting Global Airlines flights are also delayed so that the passengers can make their connections. Since Frieda’s connecting flight on Global was delayed, her first flight must have also been a delayed Global Airlines flight.

A flight on Global Airlines is delayed (X) --> all connecting Global Airlines flights are also delayed (Y)
Frieda’s connecting flight on Global was delayed (Y, partly, since we don't know if other connecting flights were delayed) --> her first flight must have also been a delayed Global Airlines flight (X)

As we can see this perfectly matches the flawed reasoning in the stimulus and is hence the correct answer.

(B) Any time that one of Global Airlines’ local ticket agents misses a shift, the other agents on that shift need to work harder than usual. Since none of Global’s local ticket agents missed a shift last week, the airline’s local ticket agents did not have to work harder than usual last week.

Any time that one of Global Airlines’ local ticket agents misses a shift (X) --> Other agents on that shift need to work harder than usual (Y)
None of Global’s local ticket agents missed a shift last week (Not X) --> T he airline’s local ticket agents did not have to work harder than usual last week (Not Y)

This does not match the reasoning structure of the stimulus. Eliminate.

(C) Any time the price of fuel decreases, Global Airlines’ expenses decrease and its income is unaffected. The price of fuel decreased several times last year. Therefore, Global Airlines must have made a profit last year.

The price of fuel decreases (X) --> Global Airlines’ expenses decrease and its income is unaffected (Y)
The price of fuel decreased several times last year (X) --> Global Airlines must have made a profit last year (some other variable, say, Z, since we don't know if decrease in cost with revenue remaining unaffected will lead to profits; it may also lead to merely lower losses)

This does not match the reasoning structure of the stimulus. Eliminate.

(D) All employees of Global Airlines can participate in its retirement plan after they have been with the company a year or more. Gavin has been with Global Airlines for three years. We can therefore be sure that he participates in Global’s retirement plan.

An employee of Global Airlines has been with the company a year or more (X) --> She can participate in its retirement plan (Y)
Gavin has been with Global Airlines for three years (X) --> We can be sure that he participates in Global’s retirement plan (some other variable, say, Z, since the option only talks about  eligibility  to participate and not actual participation)

This does not match the reasoning structure of the stimulus. Eliminate.

(E) Whenever a competitor of Global Airlines reduces its fares, Global must follow suit or lose passengers. Global carried more passengers last year than it did the year before. Therefore, Global must have reduced its fares last year to match reductions in its competitors’ fares.

A competitor of Global Airlines reduces its fares (X) --> Global must follow suit or lose passengers (Y)
Global carried more passengers last year than it did the year before (Not Y, partly, since this is also possible if it had reduced prices) --> Global must have reduced its fares last year to match reductions in its competitors’ fares (Not X)

This does not match the reasoning structure of the stimulus. Eliminate.

Hope this helps.

lewdtoucan · Answer

Hello, here's the reasoning I used to solve the problem:

the argument can be summarized as follow:

Premise: All PM know other PM's work; PM -> know other PM's work 
 Conclusion: rof M knows about the work of some PM -> M is a PM

The conclusion of the argument is based on the incorrect contrapositive of the conditinal presented in the premise.

Contrapositive: NOT(know other PM's work) -> NOT(PM)
incorrect contrapositive: Know other PM's work -> PM

Option A:

Flight delayed by G -> connecting flights delayed by G
Connecting flight delayed -> flight delayed by G
Flaw: incorrect contrapositive (treats the necessary condition as the sufficient condition)

CORRECT  becuase it commits the same logical flaw!

Option B:

miss shift -> work harder
NOT(miss shift) -> NOT(work harder)
Flaw: none. this just states that the sufficient condition is not activated therefore the necessary condition is also not activated. But notice that the structure of reasoning is not the same as in the arg
 INCORRECT

Option C:

fuel price down -> expenses down
fuel prices down last year -> profit 
Flaw: price down last year -> expense down ?? profit. the option above commits a different flaw. it make as leap from expense being down to profit. 
 INCORRECT

Option D:

Emp > 1yr -> retirement plan
G > 3yr -> retirement plan
Flaw: none, valid conditional reasoning
 INCORRECT

Option E:

Comp reduce fare -> (G reduce fare) or (lose customer)

NOT(lose customer) -> NOT(comp reduce fare)
valid contrapositive: NOT(G reduce fare) and NOT(lose customer) -> NOT(Comp reduce fare)
flaw: invalid conclusion given the conditional reasoning, AND it is not the same flaw as the one commited by the arg
 INCORRECT

Paleomycologists, scientists who study ancient forms of fungi

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Paleomycologists, scientists who study ancient forms of fungi

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615 to 715 in 15 Days (Ria's Strategies)

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