Critical Reasoning

In 1998, more citizens from the country of Monrovia migrated from Monrovia to neighboring Abstania than during any prior year. In 1998, the number of reported violent crimes in Abstania increased dramatically over 1997. The unavoidable conclusion is that Monrovians who migrated from Monrovia to Abstania were responsible for this increase.

Which of the following statements, if true, would most seriously weaken the claim that Monrovians were responsible for the increase in violent crime in Abstania during 1998?
(A) Each year more violent criminals are apprehended in Abstania than in Monrovia.
(B) During 1998 more violent crimes were reported in Abstania than in Monrovia.
(C) In 1998 no Monrovians migrated from either Monrovia or Abstania to any country other than Monrovia or Abstania.
(D) In 1998 the number of unreported violent crimes in Abstania increased as well.
(E) In 1998 fewer Monrovians migrated from Monrovia to Abstania than from Abstania to Monrovia


OA E

source : https://www.west.net/~stewart/gmat/qmcriti[4A].htm

In 1998, more citizens from the country of Monrovia migrated from Monrovia to neighboring Abstania than during any prior year. In 1998, the number of reported violent crimes in Abstania increased dramatically over 1997. The unavoidable conclusion is that Monrovians who migrated from Monrovia to Abstania were responsible for this increase.

Which of the following statements, if true, would most seriously weaken the claim that Monrovians were responsible for the increase in violent crime in Abstania during 1998?
(A) Each year more violent criminals are apprehended in Abstania than in Monrovia.
(B) During 1998 more violent crimes were reported in Abstania than in Monrovia.
(C) In 1998 no Monrovians migrated from either Monrovia or Abstania to any country other than Monrovia or Abstania.
(D) In 1998 the number of unreported violent crimes in Abstania increased as well.
(E) In 1998 fewer Monrovians migrated from Monrovia to Abstania than from Abstania to Monrovia

Tough one. Guessing A.
If Abstania has historically higher numbers of criminals than Monrovia, we can argue that Monrovians are less prone to committing violent crimes on average.
B. Since this was the particular year of excessive Monrovian immigration in to Abstania, it doesn't rule out the possibility that the parity is due to the Monrovians.
C. not relevant
D. Again, could've been due to the Monrovian population
E. not relevant.

thetrystero wrote:

In 1998, more citizens from the country of Monrovia migrated from Monrovia to neighboring Abstania than during any prior year. In 1998, the number of reported violent crimes in Abstania increased dramatically over 1997. The unavoidable conclusion is that Monrovians who migrated from Monrovia to Abstania were responsible for this increase.

Which of the following statements, if true, would most seriously weaken the claim that Monrovians were responsible for the increase in violent crime in Abstania during 1998?
(A) Each year more violent criminals are apprehended in Abstania than in Monrovia.
(B) During 1998 more violent crimes were reported in Abstania than in Monrovia.
(C) In 1998 no Monrovians migrated from either Monrovia or Abstania to any country other than Monrovia or Abstania.
(D) In 1998 the number of unreported violent crimes in Abstania increased as well.
(E) In 1998 fewer Monrovians migrated from Monrovia to Abstania than from Abstania to Monrovia

Tough one. Guessing A.
If Abstania has historically higher numbers of criminals than Monrovia, we can argue that Monrovians are less prone to committing violent crimes on average.
B. Since this was the particular year of excessive Monrovian immigration in to Abstania, it doesn't rule out the possibility that the parity is due to the Monrovians.
C. not relevant
D. Again, could've been due to the Monrovian population
E. not relevant.

Just saw the OA. Makes total sense. It's the net flow that matters.

definitely E

Though I got the answer right as E, by elimination, as rest of the options seems irrelevant.
But I am still not able to find a logical reason for justifying E.
Why would reported crimes in Abstania increase dramatically, if more Abstanians migrated to Monrovia than the number of Monrovians who migrated to Abstania.

I was looking at an option that would say that there was some other reason than the migration of Monrovians to Abstania, that led to increase in crimes.
That would have weakened the arg.

A is out as :the word 'dramatically' rules it out.

anshulseth wrote:Though I got the answer right as E, by elimination, as rest of the options seems irrelevant.
But I am still not able to find a logical reason for justifying E.
Why would reported crimes in Abstania increase dramatically, if more Abstanians migrated to Monrovia than the number of Monrovians who migrated to Abstania.

I was looking at an option that would say that there was some other reason than the migration of Monrovians to Abstania, that led to increase in crimes.
That would have weakened the arg.

A is out as :the word 'dramatically' rules it out.

What is the source of the question? I find it difficult as well to justify E. Net migration flow is not strong. Doesn't weaken. Suppose only criminals migrate to A while only non-criminals migrate to M from A. The net then would mean that more good people would be in M and more bad people in A. This would strengthen the argument not weaken it. I am not convinced.

Yeap E is correct-
claim is "Monrovians who migrated from Monrovia to Abstania were responsible for this increase".
JustIfication for E- As there were fewer Monrovians migrated from Monrovia to Abstania than from Abstania to Monrovia in that year. It weakens the arg claiming Monrovians people responsible for these crimes…..as more people migrated from from Abstania to Monrovia but Monrovia did not notice the increase in crime rate so that support the idea that migrated people do not involved in crimes

While my primary area of expertise is not writing GMAT questions, I would judge that this question is not realistic to the test.

This question is still good practice for a number of points for the right method for Critical Reasoning questions. Ask yourself whether you read the question stem first and identified the question type before moving on to the stimulus (step one of the proper method). Also, when you read the stimulus, you should have had three predictions as to what the answer was:

1) Since there is a causal argument, that’s very possibly the flaw. Causal arguments tend to overlook other possibilities – most dramatically, the possibility that something else was the cause of the phenomenon in question. I.e., the argument says A->B, but in reality, C->B.

2) Numbers vs. proportions. Arguments in CR questions frequently confuse or improperly mix measures of absolute numbers with measures of rates. We are told about the numbers of crimes, and the number of migrants, but since we don’t know the sizes of the populations, we don’t know anything yet about (for example) Abstania’s actual crime RATE. (The word “dramatically” slightly mitigates this error by implying that what’s being considered is actually a proportion, making the error a bit too subjective for a proper test question imho.)

3) Lastly, you can always use a more traditional approach for dissecting the argument and looking for a critical assumption.

Those are the things you should be thinking about before even looking at the answer choices.

A) neither weakens or strengthens the argument, because we don’t know the percentage apprehended, only the absolute numbers. Monrovia could be a lawless terror zone, with lots of unresolved crime. Or, law enforcement could be equally effective in both countries, in which case A) would imply that Monrovia has less crime than Abstania.

B) doesn’t tell us much either, because we don’t know the population of either Abstania or Monrovia. Abstania could be much much larger than Monrovia, in which case its crime rate would actually be low compared to Monrovia’s, or something more like the opposite could be the case.

C) might be relevant if we were trying to compare Monrovia’s crime rate with Abstania’s, but we don’t have even close to enough information to make that comparison, so it’s irrelevant.

D) just adds a bit of zest to to the increase in the number of crimes. It has nothing to do with the argument, which hinges on connecting this increase with the migration.

E) is, in fact, closest to the problem with this argument mentioned in 2) above. If the argument had stated, “The unavoidable conclusion is that Monrovians were responsible for this increase”, without the phrase, “who migrated from Monrovia to Abstania”, then E would be a decent weakener. As it is, the argument isn’t even clearly asserting that the number of Monrovians in Abstania has increased. Maybe the overall number of Monrovians in Abstania decreased, but in 1998 a fleet of gangster motorcycle rebels come from Monrovia, a really bad lot, and they caused the crime. So E) is not a critical assumption of the argument, as it stands. Nevertheless, it is the best weakener, since it does give us a bit more information toward actually being able to compare the crime rates.

Weaken and strengthen questions won’t always attack a critical assumption in the argument, so the fact that a critical assumption isn’t addressed in these answer choices is not necessarily untestlike. I wouldn’t be too worried if you found this problem perplexing, however – especially if you were mindful of points 1) through 3) above.

Surely E

In 1998, more citizens from the country of Monrovia migrated from Monrovia to neighboring Abstania than during any prior year. In 1998, the number of reported violent crimes in Abstania increased dramatically over 1997. The unavoidable conclusion is that Monrovians who migrated from Monrovia to Abstania were responsible for this increase.

Which of the following statements, if true, would most seriously weaken the claim that Monrovians were responsible for the increase in violent crime in Abstania during 1998?
(A) Each year more violent criminals are apprehended in Abstania than in Monrovia -->it's about violent rate between 1997 & 1998 of Abstania, so comparison between 2 countries is irrelevant
(B) During 1998 more violent crimes were reported in Abstania than in Monrovia -->the same as A
(C) In 1998 no Monrovians migrated from either Monrovia or Abstania to any country other than Monrovia or Abstania -->no influence
(D) In 1998 the number of unreported violent crimes in Abstania increased as well -->strengthen
(E) In 1998 fewer Monrovians migrated from Monrovia to Abstania than from Abstania to Monrovia -->best. it means there are fewer Monvoria people live in Abstaria in 1998 than in 1997, so it weakens the claim that more Monvoria people in Abstaria in 1998 cause for the increase of crime in 1998 than in 1997

I will go with option E