European traders

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by ngalinh » Thu Feb 21, 2013 9:23 am
lunarpower wrote:
as usual, the best way to explain is by analogy.

James doesn't grow facial hair. Therefore, he is probably no more than 14 years old.

choice (b): Every boy I know who is 13 or older can grow facial hair.
--> if this is true, then it actually supports the idea that james is younger than 13.
but, if we support the claim that james is younger than 13, then at the same time we're also supporting the (more inclusive) claim that he's 14 or younger.

this is a great example of "intuitive understanding"

if Ron authorized me to use the analogy, I'd use like this:

most of men over 70 have no hair left (= camps didn't have European goods after 1630).
so if you can't find any hair standing on the head of a man, he's probably over 70 (= if no European goods found in a camp, it may appear after 1630)

little note: a man without hair looks deadly fantastic! If you (readers) have no hair, don't worry. (high-tech will help)

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by lunarpower » Sun Feb 24, 2013 5:59 pm
aditya8062 wrote:To me it means the following dates :1625 ,1626,1627,1628 and 1629 .my point is that if these are the dates that this phrase meant then how can we be sure for lets say 1635 . i mean ,with the help of B i can be sure that from from 1625 to 1629 European goods were found but i cannot be sure if European goods were also found in 1635 and so it might be a case that this site that we talking might fall into 1635
right, well, this is where you have to invoke a bit of common sense and choose the most likely interpretation.
this is not just a one-off feature of this problem, by the way -- the ability to separate out reasonable from unreasonable interpretations, and to use common sense, is a central feature (perhaps even THE central feature) of GMAT CR.

in other words, if you are thinking about these things "like a computer", or with "formal logic", then oooohhh boy are you in trouble.
Ron has been teaching various standardized tests for 20 years.

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by lunarpower » Sun Feb 24, 2013 6:00 pm
in other words, if you are thinking about these things "like a computer", or with "formal logic", then oooohhh boy are you in trouble.
--

as another example of what i'm talking about here, consider #64 in OG13 / #65 in OG12 -- the problem about the ancient city of kourion. (I can't reproduce the problem here.)

the correct answer choice says, basically, that coin production in kourion suddenly just stopped -- out of nowhere -- in the year AD 365.

to solve this problem, you have to equate that abrupt end of production with the idea of DISASTER. this is a common-sense connection; a computer wouldn't ever make it, no matter how many "rules" had been programmed into the computer's memory.

note, also, that you have to REJECT all the other interpretations that might come to mind -- on the basis that they just aren't reasonable.
e.g.
What if, in AD 365, the emperor of Kourion realized that there was lots of inflation, and so stopped the production of coins to stabilize the money supply? --> not strictly impossible, but clearly far-fetched.
What if, in AD 365, Kourion switched to coins made of plant materials, and so all those coins are gone because they've decayed while the previous metal coins are still there? --> again, not strictly impossible, but, now, let's be serious.

if you were a machine, there would be no way for you to tell that DISASTER is the only plausible explanation for what's described in the correct answer choice.
but, since you're a human being with common sense, you can make that distinction.

this is, in fact, the single most important purpose of strengthen/weaken/evaluate/explain questions (which are the vast majority of CR problems) -- to be impossible to solve with "formal logic". that's why they are on the test in the first place.
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by lunarpower » Sun Feb 24, 2013 6:09 pm
ngalinh wrote:most of men over 70 have no hair left (= camps didn't have European goods after 1630).
so if you can't find any hair standing on the head of a man, he's probably over 70 (= if no European goods found in a camp, it may appear after 1630)
nope. this reasoning doesn't work.
to illustrate, let's just go ahead and state that no man over 70 has hair. a bit extreme, i know, but it will help to make the point.

* if you know this, then you know that any man WITH hair is NOT over 70.

* on the other hand, you can't make any statement at all about men WITHOUT hair. sure, they could be over 70, but this statement doesn't preclude the existence of bald 30-year-olds.

Same thing, even easier to think about:
Humans have two eyes.
--> clearly, if a species doesn't have two eyes, then it's a non-human species.
--> just as clearly, if a species does have two eyes, that doesn't mean it's human! there are lots of other species with two eyes.

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by lunarpower » Sun Feb 24, 2013 6:10 pm
i think part of the problem, here, is that the statements above aren't related to what is actually in this GMAT problem.

* in your first set of parentheses, you have something about a lack of European trade goods in camps after 1630. The passage doesn't say that -- in fact, it says the opposite: In all the camps from the late 1620s (and, by extension, onward), there WERE trade goods.

* In the second set of parentheses, you've also listed the opposite of what the problem actually says. The problem's conclusion is that the camp must be from 1630 or earlier (= "no later than 1630"), but you've written that the camp must be from after 1630. be sure to read the statements carefully!
little note: a man without hair looks deadly fantastic! If you (readers) have no hair, don't worry. (high-tech will help)
there are no words for how awful i would look without my hair.
Ron has been teaching various standardized tests for 20 years.

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by ngalinh » Tue Feb 26, 2013 1:20 pm
lunarpower wrote:i think part of the problem, here, is that the statements above aren't related to what is actually in this GMAT problem.

* in your first set of parentheses, you have something about a lack of European trade goods in camps after 1630. The passage doesn't say that -- in fact, it says the opposite: In all the camps from the late 1620s (and, by extension, onward), there WERE trade goods.

* In the second set of parentheses, you've also listed the opposite of what the problem actually says. The problem's conclusion is that the camp must be from 1630 or earlier (= "no later than 1630"), but you've written that the camp must be from after 1630. be sure to read the statements carefully!

yup! I had thought I would see a "wall" (flaw in my reasoning), not a "big hole" when I even hadn't run (solve the question) yet. It doesn't hurt too much... standing up with...a white flag and lots of questions:
"What changed the information in my mind when there are only 3 elements in that argument?"

- because I read a bunch of discussion preceding and all information was jumping out in my head?
- because I already had a result in my mind and I tended to change the information to make it match? (this is also my problem)
- because I actually see something confused and really want to get out of the state of confused mind, which I really hate.

here is the quote again (I copy it from original post)
However, the camp probably dates to no later than 1630 (C-I name it)], since no European trade goods were found at the site (A), and European traders were active in the region from the 1620's onward (B).
yes, it's totally make sense when we link (C) and (B) and the answer B of the question is a strengthener:
(B) At all camps in the region that have been reliably dated to the late 1620's, remains of European trade goods have been found.


but the ugly guy is (A): doesn't make sense! anyway, it's not what I have to care about in this situation.

there are no words for how awful i would look without my hair.
:) that means you have at least some hairs. Awesome!
Last edited by ngalinh on Tue Feb 26, 2013 1:46 pm, edited 1 time in total.

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by ngalinh » Tue Feb 26, 2013 1:44 pm
---
Last edited by ngalinh on Wed Feb 27, 2013 5:59 pm, edited 1 time in total.

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by ngalinh » Tue Feb 26, 2013 8:15 pm
lunarpower wrote:i think part of the problem, here, is that the statements above aren't related to what is actually in this GMAT problem.
could I know the remaining part of the problem? Thank you.