标题: 又一道不会的prep!!! [打印本页] 作者: lllmmm 时间: 2011-4-2 17:38 标题: 又一道不会的prep!!! With a record number of new companies starting up in Derderia and with previously established companies adding many jobs, a record number of new jobs were created last year in the Derderian economy. This year, previously established companies will not be adding as many new jobs overall as such companies added last year. Therefore, unless a record number of companies start up this year, Derderia will not break its record for new jobs created.
Which of the following is an assumption on which the argument relies?
(A) Each year, new companies starting up create more new jobs overall than do previously established companies. (B) Companies established last year will not add a greater number of jobs overall this year than they did last year. (C) This year, the new companies starting up will not provide substantially more jobs per company than did new companies last year. (D) This year, the overall number of jobs created by previously established companies will be less than the overall number of jobs lost at those companies. (E) The number of jobs created in the Derderian economy last year was substantially larger than the number of jobs lost last year.作者: Rainbeauty 时间: 2011-4-2 21:47
提示: 作者被禁止或删除 内容自动屏蔽作者: sdcar2010 时间: 2011-4-2 22:05
Necessary assumption. Use negation.
New Job Created = Jobs created by "previously established companies" + Jobs created by "starup companies"
If you negate C, you have: This year, the new companies starting up will provide substantially more jobs per company than did new companies last year. If this is true, although no new jobs will be created by "old companies," it is possible that jobs created by "new companies" might exceed the total number of jobs created last yeart. Then the argument falls apart. So C is the necessary assumption.
In terms of math: A = 100 (old companies) + 200 (new companies) B = 99 (old companies) + x (new companies)
If the conclusion says that B<A, then x has to be less than 200 (last year's new job number).
C) unless a record number of companies start up this year, Derderia will not break its record for new jobs created:
Not A unless B: If A, then B; If not B, then not A.
The total new jobs created by new companies = number of new companies * average number of new jobs created in each new company. Even if the number of new companies drops or remains the same as last year, if the average number of new jobs per new company reaches a new height, the total number of new jobs might still be a record. C simply prevents that from happening.作者: 大马oz 时间: 2011-4-3 10:00
sdcar2010真是牛人啊，看到他解释了很多语法逻辑什么的，很专业，应该是教GMAT的大牛吧。呵呵。仰慕一下。
祝大家杀鸡愉快。同求祝福。作者: littlexian 时间: 2011-4-3 13:33
Answer C.
NN sdcar2010 and NN 大马oz already have nice and clear explaination. 作者: huyuhan7 时间: 2012-5-18 00:04 标题: 那B是哪里错了 B为什么不对。作者: sdcar2010 时间: 2012-5-18 00:13
B) is not necessary. If you negate B), meaning established firms hire more people than last year, that factor alone cannot guarantee an increase in the total this year because maybe the startups hire zero or only 1 person this year. So the conclusion may still hold.
