warrior1991 wrote:
AndrewN Not able to get to the meaning of this question. Can you please help.
Hello,
warrior1991. Pardon me for being so literal if my interpretation of your query is off, but I thought I would point out that this is a typical
weaken-the-argument question, one that hinges upon one of the three "under"s: undercut (strongly go against), undermine (go against), and underscore (strengthen).
Quote:
Which of the following, if true, undermines the argument above?
Here, our task is to weaken the argument, so we have to pay attention to what, exactly, that argument says. Luckily for us, this one is relatively straightforward, with a conclusion marker in
thus and everything. The passage:
Aristocrat wrote:
"Life expectancy" is the average age at death of the entire live-born population. In the middle of the nineteenth century, life expectancy in North America was 40 years, whereas now it is nearly 80 years. Thus, in those days, people must have been considered old at age that we now consider the prime of life.
Our task is to weaken this notion that a 40-year-old
in the middle of the nineteenth century must have been considered old. Since "life expectancy" is defined as
the average age at death of the entire live-born population, we cannot consider still births, but we can consider babies who were born alive but may have died soon after. Looking at the answer choices, following a linear pathway to weaken the argument, we can see that just a single answer provides a rational explanation that would hamper the argument. (It must deal with lowering the number of years of life expectancy but allow for 40-year-olds not to be considered old.)
Aristocrat wrote:
(A) In the middle of the nineteenth century, the population of North America was significantly smaller than is today.
A smaller (or larger) population has no bearing on the life expectancy. The argument could still hold regardless.
Aristocrat wrote:
(B) Most of the gains in life expectancy in the last 150 years have come from reductions in the number of infants who die in their first year of life.
Notice the hint in
most. When you come across these sorts of qualifying words (superlatives), you should take note. They tend to either lead to an overreaching statement or go out of their way to qualify a reasonable answer. If life expectancy has risen because
the number of infants who die in their first year of life has decreased in a significant way, then perhaps a 40-year-old of the time period in question would not have been considered so old after all, and the conclusion of the passage would, in fact, lose traction.
Aristocrat wrote:
(C) Many of the people who live to an advanced age today do so only because of medical technology that was unknown in the nineteenth century.
This new information provides an explanation as to why people today might live longer, but it does nothing to weaken the argument that people around the age of 40 during the middle of the nineteenth century would have been considered geriatrics.
Aristocrat wrote:
(D) the proportion of people who die in their seventies is significantly smaller today than is the proportion of people who die in their eighties.
Why are we concerned exclusively with people of today when the argument is based on people of the past? This is another easy elimination.
Aristocrat wrote:
(E) More people in the middle of the nineteenth century engaged regularly in vigorous physical activity than do so today.
Good for them, but they could still have worn out their fit bodies by the time they were 40 or so, and people at the time could have still perceived them as old. This cannot be our answer.
I hope that helps. I had a lot of fun with this one, and, as always, I appreciate your calling my attention to another question.
- Andrew