#Average #Percent #Weaken #Argument Family #Some
Question
Fast-food restaurants make up 45 percent of all restaurants in Cantaria. Customers at these restaurants tend to be young; in fact, studies have shown that the older people get, the less likely they are to eat in fast-food restaurants. Since the average age of the Canatrian population is gradually rising and will continue to do so, the number of fast-food restaurants is likely to decrease.
Which of the following, if true, most seriously weakens the argument?
(Because of copyrights, the complete official question is not copied here. You can access the question here: GMAT Club)
Difficulty: Medium
Accuracy: 72%
Based on: 7767 sessions
Solution
The Story
Fast-food restaurants make up 45 percent of all restaurants in Cantaria. – Say there are 100 restaurants in all of Cantaria, 45 of those would be Fast-Food restaurants.
Customers at these restaurants tend to be young; in fact, studies have shown that the older people get, the less likely they are to eat in fast-food restaurants.– A typical customer at these Fast-Food restaurants is young. According to some studies, with age people tend to eat less often in Fast-Food restaurants. (Both these ideas are about general trends. There very well could be old people who eat at such restaurants. And there very well could be young people who do not.)
Since the average age of the Canatrian population is gradually rising and will continue to do so, the number of fast-food restaurants is likely to decrease.– The average age of Cantaria’s population is gradually increasing. This trend will continue.
Therefore, the number of Fast-Food restaurants is likely to decrease.
Gist:
The number of Fast-Food restaurants in Cantaria is likely to decrease (main point).
Because:
1. Fast-food restaurants are frequented more by young people than they are by old people.
2. With age, people tend to eat less in fast-food restaurants.
3. The average age of Cantaria’s population will keep on rising.
Gap(s) in logic:
Notice the wording: The number of Fast-food restaurants is likely to decrease.
The argument only gives us relative figures.
* % of Fast-food restaurants
* Average age trends.
To conclude about the number of restaurants based on these general trends is flawed.
- If the average age of the population is going up, that would mean that young people would constitute a smaller percentage of the population. But, it doesn’t necessarily mean that the number of young people would also be reducing. If the overall population is increasing, Cantaria could still have more young people even if as a percentage, they now make up of a smaller part.
- Even if, let’s say, the target consumers of fast-food restaurants decrease (or their revenues or profits decrease), there could be a trend that fast-food restaurants reduce the capacity per restaurant and increase more smaller kiosks and stalls, thereby still increasing the number of fast-food restaurants.
Answer choice analysis
Which of the following, if true, most seriously weakens the argument?
Framework:
We’re looking for an answer choice that would reduce our confidence in the main point that the number of fast-food restaurants is likely to decrease.
i.e., when I add the correct answer choice to the argument, I get a sense that perhaps the number of fast-food restaurants will not reduce.
Answer choice analysis
Answer Choice: A
Incorrect
Selected by: 3%
This one is going in the opposite direction. If each fast-food restaurant can serve more customers, I believe more than I did earlier that the number of fast-food restaurants will decrease. If each restaurant can serve more customers they will probably need fewer such restaurants. This answer choice strengthens the argument.
Answer Choice: B
Incorrect
Selected by: 21%
The argument deals with likelihoods and trends.
* Customers tend to be young.
* The older people get the less likely they are to eat in a fast-food restaurant.
So, there very well may be some older people who eat at fast-food restaurants more frequently than the average young person.
This piece of information does not change my belief in the argument.
Note: This answer choice is not indicating any trend. Nothing like:
* the average age of fast-food restaurant customers is going up
* or that older people are starting to eat at fast-food restaurant more frequently than before.
Let’s take an example:
Say Americans tend to be taller than Indians.
Does this statement mean that EVERY American is taller than the average Indian?
No, right? Some Indians could be taller than the average American.
Similarly, the given argument does not indicate that every older person eats at fast-food restaurants less frequently than the average young person. This option does not change my belief in any of the trends mentioned in the passage.
No impact.
Answer Choice: C
Incorrect
Selected by: 2%
Irrelevant. What people do when they do not eat in fast-food restaurants doesn’t matter. This answer choice doesn’t help me understand anything about whether the number of fast-food restaurants will reduce.
No impact.
Answer Choice: D
Correct
Selected by: 73%
Bingo! The argument was based on the fact that the average age of the population is rising (i.e. the proportion of young people in the population is decreasing). Now that I learn that the overall population is growing steadily, I’m thinking that in that case perhaps the number of young people will not go down in Cantaria, even if their proportion is decreasing. This answer choice is in line with the first gap mentioned above.
Note: This answer choice does not guarantee that the number of young people will increase. But that’s the beauty of ‘weaken’ questions. We’re not looking for an answer choice that makes the conclusion impossible. We’re looking for an answer choice that reduces our confidence. This one does that.
Answer Choice: E
Incorrect
Selected by: 1%
This could be the reason for why ‘the older people get, the less likely they are to eat in fast-food restaurants’. We already knew that older people are less likely to eat in fast-food restaurants. Now we learn that perhaps they eat more of their meals at home. Beyond that, this answer choice doesn’t add anything to the argument.
No impact.
If you have any doubts regarding any part of this solution, please feel free to ask in the comments section.
Anish Passi
GMAT Coach
With over a decade of GMAT training experience, top 1 percentile scores on the CAT and GMAT, and a passion for teaching, I’d like to believe I am quite qualified to be a GMAT coach. GMAT is learnable, and I help students master the GMAT through a process-oriented approach based on logic and common sense. I offer private tutoring and live-online classroom courses. My sessions are often sprinkled with real-world examples, references to movies, and jokes that only I find funny. You’ve been warned 🙂