The University sponsors both a Volunteers group, whose

D it is.

Arguments:
5 A and 4 V damages stuff => A is more dangerous

But if we were to show that 5A in the total of 1000 A and 4V in a total of 8 V, we can see that V is much more dangerous.

Explanation for choice D

Type: weaken

Conclusion: anarchists are more likely to vandalize than Volunteers

Assumption: the number of arrested members of two groups is representative for the vandalism tendency between two groups.

Weaken: the Assumption. Hence choice D is correct

a little query here, if anyone can enlighten me on this;

generally if any option has a percentage constraint attached to it, we consider that wrong. reason being that the percentages are calculated on the basis of numbers and we are not sure of the numbers were too many or too few.

But if the argument mentions numbers explicitly, is it safe to consider percentages then???

It really depends on what the question is asking, in this question a conclusion is made that Anarchists are far more likely to vandalize university property than are Volunteers
if we want to compare likeliness of 2 group, % of people doing an act out of the total of the group is more accurate a measure than comparing the number...

I selected B but i think my mistake was following. Can someone review and share their inputs?

Last year, five Anarchists were arrested by campus police for acts of vandalism, while only
four Volunteers were arrested for acts of vandalism on campus.
Therefore, Anarchists are far more likely to vandalize university property than are Volunteers.

Argument is making the conclusion based upon the # of arrest made.

Which of the following would best help to expose a flaw in the reasoning to the above?

B Vs D:

B) Discussing the percentage of total acts of vandalism on campus that were performed by Volunteers and Anarchists, respectively.

Let the total acts of vandalism =100
% of V done by Vol. =80
% of V done by Ana =20
Or otherwise.
IMO even this information is relevant in evaluating the conclusion. However, option D addresses the mentioned premise directly hence preferred over B.

D) Comparing the total percentage of Volunteers who were arrested for acts of vandalism with the total percentage of Anarchists who were arrested for acts of vandalism.

Hi Experts,

Please suggest why option B is wrong here?

Premises:
The University sponsors Volunteers and Anarchists.
Last year, five Anarchists were arrested for vandalism, while only four Volunteers were arrested for vandalism.

Therefore, Anarchists are far more likely to vandalize university property than are Volunteers.

Note that the conclusion says Anarchists are far more likely to vandalise.

The logical numbers for comparison would be "10% Anarchists vandalised" while only "2% volunteers vandalised" or something similar.
We need to compare the percentage of volunteers who were arrested with percentage of anarchists who were arrested to arrive at the conclusion.
Say,
If there are 200 volunteers and 4 of them were arrested but if there are only 50 anarchists and 5 of them were arrested, then we can say that anarchists are far more likely to vandalise. So (D) will help us give a sense of the comparison and is correct.

B) Discussing the percentage of total acts of vandalism on campus that were performed by Volunteers and Anarchists, respectively.
We are already given that anarchists vandalised more than volunteers. Whether both constitute a small percentage of total acts or a large percentage, is immaterial. We need to compare the two of them with each other, not with the rest.

Answer (D)

Okay I think there is a flaw in option D. The option says Compare the total percentage of Volunteers who were arrested for acts of vandalism. To determine which group is dangerous we need to know all the acts not just when they got arrested. Put in other ways, Volunteers might be doing less crimes but are getting caught more often by the police. This doesnt show that Volunteers are more dangerous. Actually they are less dangerous incase Activits are pro at not getting caught. Thoughts? Am i over thinking this?

Hi Akadmin,

See the Conclusion - It says - Therefore, Anarchists are far more likely to vandalize university property than are Volunteers.

more likely means chances are >50%

question stem asks to find an option which would best help to expose a flaw in the reasoning in the stimulus.
Conclusion is drawn based on small sample of data. Inorder to expose the flaw in the reasoning we need to Compare the total percentage of Volunteers who were arrested for acts of vandalism with the total percentage of Anarchists who were arrested for acts of vandalism as in D)

For example if there are If there are 100 volunteers and 10 of them were arrested (10%) but if there are only 50 anarchists and 10 of them were arrested then (20%), then we can say that anarchists are far more likely to vandalise

I have a query here.

It has been mentioned in the argument as "Therefore, Anarchists are far more likely to vandalize university property than are Volunteers"

Means A is more likely to cause damage to the properties than V. This conclusion was arrived based on the arrest head-count.

So there are two things flaw in the reasoning:

1. Reason 1 - We don't know the total number of people present in each group. Based on arrest alone we cant come to conclusion. Option D address this.

2. Reason 2 - Based on the number they are concluding that A cause more damage than V. But without knowing what is the total damage caused by A and damage caused by B how can we say that A caused more damage than B. Option B is addressing this. Can you clarify why B is wrong?

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.