新手求助！请大家帮忙解答几个题呀~！

CraigGMAT

2.  假设题 Press Secretary: Our critics assert that the President's recent highway project cancellations demonstrate a vindictive desire to punish legislative districts controlled by opposition parties. They offer as evidence the fact that 92percent of the projects canceled were in such districts. However, all of the canceled projects had been identified as inefficient in a report written by respected nonpartisan auditors. So the President's choice was obviously motivated by sound budgetary policy, not partisan politics.


Which of the following is an assumption on which the press secretary's argument depends?


正解： The scheduled highway projects identified as wasteful in the report were not mostly projects in districts controlled by the President's party.


LZ实在是。。没有想明白中间的逻辑关系……><

Okay, first of all... always CAP the arg. That means, write the conclusion, then the premise, then the assumptions. I’ll work through it thusly:

Conclusion: The president made his decision for budgetary reasons.

Premise Why? Well, we know that the president only cancelled projects that had proven themselves to have a bad budget. He got rid of all projects that were losing money.

Let’s explore this:

How Did They Do That Research? A non-partisan (ie. Belonging to neither party) research team made the list, and the president simply said... okay, get rid of those projects.

So, why are the opposition party angry? Of all the projects that were cancelled, 92% of them were from the opposition party district. This inequality makes the opposition party believe that the president is out to hurt them. They claim, ‘Hey! You mostly only got rid of our projects. That’s totally biased.’

The Assumption: We have to assume that the argument is correct. The conclusions was that it was from budgetary reasons, not political reasons. So, we have to assume that (1) the president listened to the committee & (2) the president only deleted projects that were on the list.

Thus, the projects that were ineffiencent, 92% of them came from the opposition party district (or, alternatively, the presidents party district does NOT have that many with inefficiencies)

Hope that helps.


Craig

CraigGMAT

3. 评价题  The FMD， foot and mouth disease is caused by a virus transmitted to humans by deer ticks. Generally, deer ticks pick up the virus while in the larval stage by feeding on infected black mice. However, certain other species on which the larvae feed do not harbor the virus. If the population of these other species were increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the virus would likely decline.


正解 Whether the deer tick population's size is currently limited by the capability of animals for the tick's larval stage to feed on


LZ太菜了……这个……也没想明白其中的逻辑关系……

First thing, always post the question. You sent the argument, but I don’t really know if you are trying to strengthen, weaken, or find the assumption.

But, from the answer it looks like the question was kind of like

Which of the following would be a question we need to know in order to prove this argument correct.

The argument is basically saying,

1) We get this disease from ticks.
2) Ticks get this disease when they are larvae
3) As larvae, ticks stay in a bunch of animals.
4) When the larvae happen to stay in the mouse, they get this particular disease.

5) If the larvae stay in a different animal, they WONT get this particular disease
6) If we want to stop this disease, we need to release more of these animals.

Okay. That is making a few assumptions. The first assumption is that, basically, by releasing more of the “other” animals (who knows... opossums or something), then there will be less mice to give the disease.

It’s making an assumption that is mathematical in nature. There are a limited number of larvae hosts. Some give the disease, others do not. If the number of hosts increase, the number of deer ticks stay the same. Thus, if the number of “alternative” hosts increase, there is a greater chance to decrease the diseased population.

If we were to assess this argument, we would need to know whether or not that assumption is true. That is, we need to know if the deer tick population is fixed or growing. If it’s growing as we add more hosts, then no, the diseased POPULATION wont decrease, but the PERCENTAGE will decrease. See? It’s a math question.

Protip: Whenever there is a GMAT CR question involving anything that REMOTELY resembles average increases, they conclude that the total increase... but that’s not necessarily true.)


Craig

CraigGMAT

4. 加强题 Mayor Centralia's critics complain about the jobs that were lost in the city under Centralia's leadership. But the fact is that not only were more jobs created than were eliminated, but the average pay for these new jobs has been higher than the average pay for jobs citywide every year after Centralia took office. Therefore, there can be no doubt that throughout Centralia's tenure the average paycheck in this city has been getting steadily bigger.


正解 The average pay for jobs eliminated in the city during Mayor Centralia's tenure has been roughly equal every year to the average pay for jobs citywide.


LZ。。还是没有理解逻辑关系……

I don’t know the question, again, but from the right answer it looks like another “mathy” question. I’ll give a quick answer. If you don’t get it, send another post and we’ll do our best.

The conclusion is that the average paycheck NOW has grown, because of two facts:

1) lost jobs have been replaced
2) the new jobs are higher pay

But, that’s not good enough. He is assuming that (1) all pay is steady & 2) those who did not lose jobs have had increases in pay & 3) the jobs lost vs jobs gained are at such a level that it makes no difference about non-lost jobs.

But, if the answer is right (if the avg pay is roughly equal to all people in teh city), then we can see that the lost jobs wont affect the income growth.


Craig

CraigGMAT

5.一道有点小陷阱的加强题 An unexpected increase in the production of elephant ivory artifacts on the Nigerian coast of North Africa occurred in the eleventh century. Historians clarify this increase as the consequence of an area opening up as a new source of ivory and argue on this basis that the important medieval trade between North Africa and West Africa began at this period.


Each of the following, if true, provides some support for the historians' account described above EXCEPT?
A. In West Africa gold coins from Nigerian North Africa have been found at a tenth- century but at no earlier sites.
D. Documents from Nigerian Europe and North Africa that date back earlier than the eleventh century show knowledge of West African animals.
答案是D。。可是 lz反而觉得。。D可以加强结论，所以D不应该被排除，也就是说。。答案不应该是D。。。混乱了……

D does not make it stronger, because the conclusion is that the European/African trade started in the 11th Century because of the ivory. But D says that the trade started EARLIER than the 11th century. That would show that the conclusion is wrong -- that something ELSE caused the trade between African & Europe. Make sense?


Hope this helps !


Craig

271632852

第一题的答案OG13版98题，答案B：The first provides support for the conclusion of the argument; the second identifies the content of that conclusion.
但我不明白第一句话为什么有support for theconclusion的作用？求解！

metesici

十分感謝Craig的解答！清晰明了！