Increasing crime commited by teens

Citizens of Parktown are worried by the increased frequency of serious crimes committed by local teenagers. In response, the city government has instituted a series of measures designed to keep teenagers at home in the late evening. Even if the measures succeed in keeping teenagers at home, however, they are unlikely to affect the problem that concerns citizens, since most crimes committed by local teenagers take place between 3pm and 6pm.

Which of the following,if true, most substantially weakens the argument ?

1) Similar measures adopted in other places have failed to reduce the no of teenagers in the late evening
2) Crimes committed by teenagers in the afternoon are mostly small thefts and inconsequential vandalism.
3) teenagers are much less likely to commit serious crimes when they are at home than when they are not at home
4) Any decrease in the need for police patrols in late evening would not mean that there could be more intensive patrolling in the afternoon
5) The schools in Parktown have introduced a number of after school programs that will be available to teenagers until 6pm on weekday afternoons

Please explain your pick.

GMATGuruNY wrote:

Citizens of Parktown are worried by the increased frequency of serious crimes committed by local teenagers. In response, the city government has instituted a series of measures designed to keep teenagers at home in the late evening. Even if the measures succeed in keeping teenagers at home, however, they are unlikely to affect the problem that concerns citizens, since most crimes committed by local teenagers take place between 3pm and 6pm.

Which of the following,if true, most substantially weakens the argument ?

1) Similar measures adopted in other places have failed to reduce the no of teenagers in the late evening
2) Crimes committed by teenagers in the afternoon are mostly small thefts and inconsequential vandalism.
3) teenagers are much less likely to commit serious crimes when they are at home than when they are not at home
4) Any decrease in the need for police patrols in late evening would not mean that there could be more intensive patrolling in the afternoon
5) The schools in Parktown have introduced a number of after school programs that will be available to teenagers until 6pm on weekday afternoons

Please explain your pick.

Premise: The city government has instituted measures to keep teenagers at home in the late evening, but MOST CRIMES committed by teenagers take place between 3pm and 6pm.
Conclusion: The new measures are unlikely to curb the increase in SERIOUS CRIMES.

Notice the change in LANGUAGE and SCOPE.
The premise is about MOST CRIMES, but the conclusion is about SERIOUS CRIMES.
MOST CRIMES ≠ SERIOUS CRIMES.
The assumption is that the CRIMES committed by teenagers between 3pm and 6pm are SERIOUS.
One way to weaken the conclusion is to show that the CRIMES committed by teenagers between 3pm and 6pm are NOT SERIOUS.

Answer choice B does just that: Crimes committed by teenagers in the afternoon are mostly small thefts and inconsequential vandalism.

The correct answer is B.

Mo2men wrote:Why E is wrong?

GMATGuruNY wrote:

Mo2men wrote:Why E is wrong?

Conclusion: The measures designed to keep teenagers home in the late evening are unlikely to affect the frequency of serious crimes committed by teenagers.

E: The schools in Parktown have introduced a number of after school programs that will be available to teenagers until 6pm on weekday afternoons.
Given that most crimes committed by local teenagers take place between 3pm and 6pm, this option implies that the number of serious crimes committed by teenagers might decrease as a result of these after-shool programs, STRENGTHENING the conclusion that the measures designed to keep teenagers home at night will NOT affect the frequency of serious crimes.
Since the correct answer choice must weaken the conclusion, eliminate E.

Mo2men wrote:
Thanks Mitch.

I have another reason to eliminate E. Is my line of reasoning true?

Choice E offers alternate plan which is not relevant to the original plan discussed in the argument.i.e We should weaken the under discussion but without offering new plan or measures. Instead, we should interpret the fact cited by the argument by a way to weaken the argument.