scarlatti
Vyshak
Younger people eat in fastfood. Average age of current population is increasing - Number of fastfood restaurants will decrease
Possible weakener: As the current population ages, younger people are added to the population
A) Fast-food restaurants in Canatria are getting bigger, so each one can serve more customers. - Incorrect - Out of context. We are not bothered about the increase in capacity of fast food restaurants.
B) Some older people eat at fast-food restaurants more frequently than the average young person. - Incorrect - Irrelevant
C) Many people who rarely eat in fast-food restaurants nevertheless eat regularly in restaurants. - Incorrect - Strengthens
D) The overall population of Canatria is growing steadily. - Correct
E) As the population of Canatria gets older, more people are eating at home. - Incorrect - Supports the argument
Answer: D
I have a problem with D. Just because Canatria´s population increased, it doesn´t mean that the number of young people in Canatria will increase, since that same increase in the population could have been due to immigration for example, and we can´t say that immigrants are young.
Vyshak, it's true that choice (D)
might not weaken the argument. We can think of scenarios, like the one you described, in which choice (D) would have no effect. But remember that we are looking for an answer choice that
most seriously weakens the argument, not an answer choice that
definitely weakens the argument.
The author says that the number of fast-food restaurants is likely to decrease because the average age is increasing. Thus, according to the author, the number of young people will probably decrease. Choice (D) seriously undermines this reasoning. If the overall population is growing
steadily ("steadily" is a key word here), then that will
probably counteract the effect of the aging.
Sure, we
might have a steady influx of older immigrants, but if we are talking about steady growth of the overall population, it is more likely that we will see increases across all ages. Choice (D) does not disprove the author's logic with 100% certainty, but it does seriously weaken the argument.
I hope that helps!