"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 an age that we now consider the prime of life.
Which of the following, if true, undermines the argument above?
If there is any fierce competition in the Asian Games in Guangzhou, the attending audience will be treated to a mesmerizing and memorable moment. But there will not be a mesmerizing and memorable moment unless there are diehard sports fans in the audience. To be a diehard sports fan, one must understand the spirit of sports.
If all the statements above are true, which one of the following statements must also be true?
A) If there are no diehard sports fans in the audience, then there will be no fierce competition in the Asian Games in Guangzhou.
B) No people who understand the spirit of sports will be in the audience if the audience will not be treated to a mesmerizing and memorable moment.
C) If there will be people in the audience who understand the spirit of sports, then at least one competition in the Asian Games in Guangzhou will be fierce.
D) The audience will be treated to a mesmerizing and memorable moment unless there are people in the audience who do not understand the spirit of sports.
E) If there are diehard sports fans in the audience, then there will be fierce competition in the Asian Games in Guangzhou.
This is a formal logic problem. In formal logic, recognition of trigger is very important. Trigger is the sufficient condition in an If ..., then ... statement.
From the stimulus: But there will not be a mesmerizing and memorable moment unless there are diehard sports fans in the audience. Or in If/then form: If there are NOT diehard sports fans in the audience, then there will not be a mesmerizing and memorable moment.
There is not statement in the stimulus with "diehard sports fans" as the trigger (sufficient condition). Therefore, E) is wrong.
The last sentence in the stimulus: To be a diehard sports fan, one must understand the spirit of sports. Or: If one is a diehard sports fan, then one understands the spirit of sports. Note: "one understands the spirit of sports" is not a sufficient condition (trigger). C) If there will be people in the audience who understand the spirit of sports, then at least one competition in the Asian Games in Guangzhou will be fierce.
C) needs "one understands the spirit of sports" to be a trigger. However, no trigger can be found in the stimulus.
1. “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 an age that we now consider the prime of life.
Which of the following, if true, undermines the argument above?
(A) In the middle of the nineteenth century, the population of North America was significantly smaller than it is today.
(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.
(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.
(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.
(E) More people in the middle of the nineteenth century engaged regularly in vigorous physical activity than do so today.