陈向东逻辑 258页-33题，求助

yhj_8888

Recent estimates predict that between 1982 and 1995 the greatest increase in the number of people employed will be in the category of low-paying service occumpation. This category, however, will not increase its share of total employment, whereas the category of high-paying service occumpation will increase its share.

If the estimates above are accurate, which of the following conclusion can be drawn?

A) In 1982 more people were working in low-paying service occumpation than were working in high-paying service occupations.

这道题的答案是A, 可我的问题是： 原文只是说了low-paying service occumpation的数量会增加，但比例不会增加。 并没有牵涉到任何low-paying service occumpation与 high-paying service occumpation的比例或是数量方面的对比。 怎么就能推出答案呢？ 请NN帮忙解答， 谢谢！

HyeHye

题干条件：
1）从1982年到1995年low-paying service occupation(LP)人数增长最多。
2) LP这类将不会增加占整就业人数的份额，然而HP占的份额却会增加。

假设 Total=LP+HP+X(X为其他就业人数)； CLP为LP增加人数；CHP为HP增加人数；CT为就业增长总人数。由上可知CLP>CHP
由条件2得:
(LP+CLP)/(Total+CT)-LP/Total不增加<=0
(HP+CHP)/(Total+CT)-HP/Total增加>0

1982年，LP与HP是没有关联的。因为CT也是个变量(即分子，分母都是变量)。他们之间的关系是1982年LP与1995年LP的可比；而无法让HP与LP相比。答案A是推不出的

yhj_8888

谢谢sdcar2010, 今天再看题目又有了不同的理解，

可否理解为原来low-paying service occupations在1982年的人数的base 大， 所以the increas in the absolute number of employment  才不会导致percentage变大呢？

must be true与conclusion类的题错得相对较多。 能否请sdcar2010分享一下做这类题目的心得？thanks in advance!!!

sdcar2010

Recent estimates predict that between 1982 and 1995 the greatest increase in the number of people employed will be in the category of low-paying service occupations. This category, however, will not increase its share of total employment, whereas the category of high-paying service occupations will increase its share.

If the estimates above are accurate, which of the following conclusions can be drawn?

(A) In 1982 more people were working in low-paying service occupations than were working in high-paying service occupations.
(B) In 1995 more people will be working in high-paying service occupations than will be working in low-paying service occupations.
(C) Nonservice occupations will account for the same share of total employment in 1995 as in 1982.
(D) Many of the people who were working in low-paying service occupations in 1982 will be working in high-paying service occupations by 1995.
(E) The rate of growth for low-paying service occupations will be greater than the overall rate of employment growth between 1982 and 1995.

This is a pure math problem. Two facts:
1) Low-paying job has the greatest increase in numbers
2) Low-paying job has no increase in percentage of the total employment, whereas the high-paying job has increased its share.

If the above is true, the A) has to be true. The reason?

If A) is not true, which would lead to at least the same amount of people were employed in both low- and high-paying jobs, then during 1982 and 1995, high-paying job would have a bigger increase in the absolute number of employment!!! This is contrary to the fact 1).