Critical Reasoning

Nice Question from old thread. OA after some discussion. got confused between two choices and chose wrong one .

Reading skills among high school students in Gotham have been steadily declining, which can only be the result of overcrowding in the schools.

Which of the following, if true, most seriously weakens the statement above.

A) The high school system in Gotham succeeds in giving students a good education at considerably less cost than do most systems.
B) Several cities have found that overcrowding in schools is not always associated with lower reading scores.
C) Gotham schools have a greater teacher-to-student ratio tham most other school systems.
D) Students' reading skills have not declined in other cities where the high schools are just as crowded as those of Gotham.
E) Schools are not overcrowded in many cities where high school reading scores have declined more than they have in Gotham.

user123321

IMO (D)

A) The high school system in Gotham succeeds in giving students a good education at considerably less cost than do most systems. --> The cost factor does not weaken the link between reading skills and overcrowding.

B) Several cities have found that overcrowding in schools is not always associated with lower reading scores.
--> Lower reading scores? The question here is skills. Besides the argument states that lower reading skills are because of overcrowding and not vice-versa.

C) Gotham schools have a greater teacher-to-student ratio tham most other school systems. --> So? Nothing in this to weaken the link.

D) Students' reading skills have not declined in other cities where the high schools are just as crowded as those of Gotham. --> Perfect. Compared to schools in other cities, Gotham schools have a similar situation. Yet the other cities schools do not have worse skills.

E) Schools are not overcrowded in many cities where high school reading scores have declined more than they have in Gotham. --> Not about the scores. The argument is about skills.

Good one. I struggled.

Reading skills among high school students in Gotham have been steadily declining, which can only be the result of overcrowding in the schools.

argument reasoning:

Overcrowding(X) ======> (Y)declining reading skills in Gotham school;

i.e. X is the reason,
weaken by Some thing else may be the reason;

A) The high school system in Gotham succeeds in giving students a good education at considerably less cost than do most systems.
--doesn't matter
B) Several cities have found that overcrowding in schools is not always associated with lower reading scores.
-- means other schools found most times over crowding is the reason. ( strengthens)
C) Gotham schools have a greater teacher-to-student ratio tham most other school systems.
-- They should perform better but still performing bad ==> overcrowding may be the reason;-- strengthen;
D) Students' reading skills have not declined in other cities where the high schools are just as crowded as those of Gotham.
-- then why is declining in Gotham? may be after all overcrowding is not the reason, may be something else.--- weaken contender.
E) Schools are not overcrowded in many cities where high school reading scores have declined more than they have in Gotham.
-- so they have problems causing the decline -but can we say overcrowding is not the reason at Gotham?

IMO (D) --

(E) is a potential weaken contender in the absence of (D).

Personalize with choice(D):

A: My school is overcrowded, reading skills are declining
B: Other schools have overcrowded too, but they are not declining

--
Personalize with choice (E):
A: My school is overcrowded, reading skills are declining
B: Other schools not overcrowded, but they are declining..
A: Yea, but they have other problems, student teacher ratio is very bad in some schools

Choice(D) is a stronger argument.

oops... (E) has "reading scores" not reading skills. I missed this one. easy cross out.

OA is E

src:wikipedia
Necessary causes:
If x is a necessary cause of y, then the presence of y necessarily implies the presence of x. The presence of x, however, does not imply that y will occur.
Sufficient causes:
If x is a sufficient cause of y, then the presence of x necessarily implies the presence of y. However, another cause z may alternatively cause y. Thus the presence of y does not imply the presence of x.

here overcrowding(x) is necessary cause of y(declining of reading skills).
D says x occurred but y didn't occur. so this is not weakening the problem
E says x did not occurred but y occured which is wrong & is weakening the problem.

HTH.

user123321


user123321

user123321 wrote:OA is E

src:wikipedia
Necessary causes:
If x is a necessary cause of y, then the presence of y necessarily implies the presence of x. The presence of x, however, does not imply that y will occur.
Sufficient causes:
If x is a sufficient cause of y, then the presence of x necessarily implies the presence of y. However, another cause z may alternatively cause y. Thus the presence of y does not imply the presence of x.

here overcrowding(x) is necessary cause of y(declining of reading skills).
D says x occurred but y didn't occur. so this is not weakening the problem
E says x did not occurred but y occured which is wrong & is weakening the problem.

HTH.

user123321


user123321

Based on your own explanation, the OA should be D.

here (X)Overcrowding is necessary condition & (Y)declining of reading skills is the effect.
according the causality, the presence of X it doesn't imply that y will occur.
i.e (X) overcrowding is present in those schools doesn't mean that (Y) students reading skills must decline.
=> 1) overcrowding can occur & students reading skills can decline or
2) overcrowding can occur & students reading skills didn't decline
both are true.

That is what option D says. From that option we cannot say the problem statement got weakened

not sure if this helped. I suck in explaining things

user132321

user123321 wrote:here (X)Overcrowding is necessary condition & (Y)declining of reading skills is the effect.
according the causality, the presence of X it doesn't imply that y will occur.
i.e (X) overcrowding is present in those schools doesn't mean that (Y) students reading skills must decline.
=> 1) overcrowding can occur & students reading skills can decline or
2) overcrowding can occur & students reading skills didn't decline
both are true.

That is what option D says. From that option we cannot say the problem statement got weakened

not sure if this helped. I suck in explaining things

user132321

Reading skills among high school students in Gotham have been steadily declining, which can only be the result of overcrowding in the schools.
Which of the following, if true, most seriously weakens the statement above.

It states that decline in reading skills can only be attributed to the overcrowding in schools. The premise that will weaken this argument will state that decline can be attributed to some other factor as well or will directly attack the correlation between overcrowding and reading skills.

D) Students' reading skills have not declined in other cities where the high schools are just as crowded as those of Gotham.
In D, comparison has been done among the reading skills of students in different cities by keeping the crowd at those schools (almost) same (which is just to reach a meaningful conclusion). Further, it has implied that decline in skills was not observed at those schools but in (Gotham's case only). This implies that the decline observed cannot be attributed to overcrowding as the argument presumed. Hence, D weakens the argument.

*Kindly correct me if i am wrong.

user123321 wrote:here (X)Overcrowding is necessary condition & (Y)declining of reading skills is the effect.
according the causality, the presence of X it doesn't imply that y will occur.
i.e (X) overcrowding is present in those schools doesn't mean that (Y) students reading skills must decline.
=> 1) overcrowding can occur & students reading skills can decline or
2) overcrowding can occur & students reading skills didn't decline
both are true.

That is what option D says. From that option we cannot say the problem statement got weakened

not sure if this helped. I suck in explaining things

user132321

E shows that reading scores/skills can decline for reasons other than over crowding.

D shows that overcrowding doesn't necessarily cause reading scores to decline.

The argument is that overcrowding can be the only cause of decline. E is the better choice.

To my & your surprise, E is OA

Here declining of reading skills is only caused by result of overcrowding in the schools.
It doesn't mean declining of reading skills is always caused by result of overcrowding in the schools.

The statement means, whenever reading skills decline, overcrowding will be the cause. It means if overcrowding happens, it is not required for reading skills to decline, it may or may not.

user123321

What I don't understand is, if I prove X is not the reason, am I not proving others could be the reason? Kill to birds at a time.

Also, from the question stem, the conclusion is
"Over crowding is the only reason declining reading skills at Gotham school.;

"At Gotham school" is important;

Am I missing some thing?

Also, If change the question stem "only" to "must be"

Reading skills among high school students in Gotham have been steadily declining, which must be the result of overcrowding in the schools.

Does the answer choice really changes? It still means the same thing... Over Crowding is the reason for declining.

correct choice is E

Conclusion: overcrowding (X) cause lower reading skills (Y)
Choice E stated that: X not happen, Y still happen. Weaken.

I posted an explanation here:

https://www.beatthegmat.com/declining-re ... 81954.html