Critical Reasoning

Hi,

Example 1

Statement
All trees are green

Answer choices
a) Some trees are green
b) Many tress are green

Example 2

Statement
All grass is green

Answer choices
a) Some grass is green
b) Most grass is green

Query
which answer choice is equivalent to the statement in the above examples or both the answer choices are incorrect???

The reason behind this query is few days before I faced a CR problem and in its solution it was mentioned that "Many" is same as "All". Is that true that in CR words such as "Most" and "Many" are equivalent to ALL????

- If its true then are there any more words in CR which have same meaning as above??? ex: "More", "Some"

Please clarify my doubts? I know it may be an invalid or silly question. However I am confused at this moment with such words.

Thanks and regards.



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Hi enjoystar,

What you are mentioning relates to 'Formal Logic'.(LSAT Reasining bible explains it very well). I am just copying an excerpt from the same.

"
The Logic Ladder details the inherent relationship between all, most, and some:
All ---> Most ------> Some

In the Ladder, each term represents a “rung,” and the upper rung terms automatically imply that the lower
rung terms are known to be true. Thus, if you have an all relationship, you automatically know that the
most and some relationships for that same statement are true. So, if a statement is made that “All waiters
like wine,” then you immediately know that “Most waiters like wine,” and “Some waiters like wine.”
The same is true for most relationships, but to a more limited extent. If “Most waiters like wine,” then you
automatically know that “Some waiters like wine.” But, because most is below all on the Logic Ladder,
you do not know with certainty that “All waiters like wine” (it is possibly true, but not known for certain).
This reveals a truth about the Logic Ladder: the upper rungs automatically imply the lower rungs, but the
lower rungs do not automatically imply the upper rungs. In other words, as you go down the rungs the
lower relationships must be true, but as you go up the rungs the higher relationships might be true but are
not certain. "

Hope this would give you a better understanding of logical relationship among these different words.


Thanks
Komal

joshi.komal wrote:Hi enjoystar,

What you are mentioning relates to 'Formal Logic'.(LSAT Reasining bible explains it very well). I am just copying an excerpt from the same.

"
The Logic Ladder details the inherent relationship between all, most, and some:
All ---> Most ------> Some

In the Ladder, each term represents a “rung,” and the upper rung terms automatically imply that the lower
rung terms are known to be true. Thus, if you have an all relationship, you automatically know that the
most and some relationships for that same statement are true. So, if a statement is made that “All waiters
like wine,” then you immediately know that “Most waiters like wine,” and “Some waiters like wine.”
The same is true for most relationships, but to a more limited extent. If “Most waiters like wine,” then you
automatically know that “Some waiters like wine.” But, because most is below all on the Logic Ladder,
you do not know with certainty that “All waiters like wine” (it is possibly true, but not known for certain).
This reveals a truth about the Logic Ladder: the upper rungs automatically imply the lower rungs, but the
lower rungs do not automatically imply the upper rungs. In other words, as you go down the rungs the
lower relationships must be true, but as you go up the rungs the higher relationships might be true but are
not certain. "

Hope this would give you a better understanding of logical relationship among these different words.


Thanks
Komal

Hi Komal,

Yes I am referring Powerscore LSAT Bible LR book and in that some where in the earlier chapters it was mentioned as in my previous post.

I will go through the Formal Logic chapter of LR.

I have following queries for you as I guess ur also studying from powerscore LSAT bible.

In the book the CR question types are mentioned as follows:

1. Must Be True/Most Supported
2. Main Point
3. Point at Issue
4. Assumption
5. Justify the Conclusion
6. Strengthen/Support
7. Resolve the Paradox
8. Weaken
9. Method of Reasoning
10. Flaw in the Reasoning
11. Parallel Reasoning
12. Evaluate the Argument
13. Cannot Be True

Queries
---------
1) Please let me know which Question types I have to study from above for GMAT CR?
2) Also there are chapters "Numbers and Percentages" ,"Formal Logic"
and "Conditional Logic" in the book do I have to sutdy these chapters for GMAT?

Thanks and regards.

Just a quick word (while I'm between classes):

All does NOT imply many, most or some.

"Many", "most" and "some" are all terms that presuppose existence. For example, when we say that some people eat cheese, that means that there's at least one person who eats cheese.

However, all does NOT presupposed existence. We can rewrite any "all A are B" statement as "if A then B". For example, "all unicorns have one horn" really means "if something is a unicorn, then it has one horn", and doesn't imply that any unicorns actually exist.

So:

"All" means 100%, but is conditional.

"Most" means more than 50%.

"Many" is an unspecified % and could just mean 1.

"Some" means "at least one".

Stuart Kovinsky wrote:Just a quick word (while I'm between classes):

All does NOT imply many, most or some.

"Many", "most" and "some" are all terms that presuppose existence. For example, when we say that some people eat cheese, that means that there's at least one person who eats cheese.

However, all does NOT presupposed existence. We can rewrite any "all A are B" statement as "if A then B". For example, "all unicorns have one horn" really means "if something is a unicorn, then it has one horn", and doesn't imply that any unicorns actually exist.

So:

.

"Most" means more than 50%.

"Many" is an unspecified % and could just mean 1.

"Some" means "at least one".

Hi Stuart,

I understood the point u were trying to make in the above post that "All" means 100%, but is conditional.

However can you explain these "All", "Most" and "Many"words in the context of CR stimulus??? Because many answer options words confuse the test takers in these words and in some answers these words are considered equivalent

I will go through LSAT LR Bible soon however before that if u can throw some light on the above words, I will be grateful to you

Thanks and regards,
Enjoystar

Stuart Kovinsky wrote:Just a quick word (while I'm between classes):

All does NOT imply many, most or some.

"Many", "most" and "some" are all terms that presuppose existence. For example, when we say that some people eat cheese, that means that there's at least one person who eats cheese.

However, all does NOT presupposed existence. We can rewrite any "all A are B" statement as "if A then B". For example, "all unicorns have one horn" really means "if something is a unicorn, then it has one horn", and doesn't imply that any unicorns actually exist.

So:

"All" means 100%, but is conditional.

"Most" means more than 50%.

"Many" is an unspecified % and could just mean 1.

"Some" means "at least one".

Hi Stuart/Komal,

I just skimmed over LSAT LR Formal logic topic and i understood little bit
what you mean by following things:

"All" means 100%, but is conditional.
"Most" means more than 50%.
"Some" means "at least one".

However, I have the following query:

Can I equate "Most" to "Many" and "Some" to "Few"
and come up with the following sentences:

--------------------------------------------------------
"Most" means more than 50%.

Therefore,
"Many" means more than 50%.
--------------------------------------------------------
Also,
"Some" means "at least one".

Therefore,
"Few" means "at least one".
--------------------------------------------------------

Are the above sentences correct???

If not please tell me the meaning of words "Many" and "Few" in terms of percentage or Numeric like you mentioned the words "Most", "Some" and "All".

Thanks and regards,

"Many" does NOT mean "most". The best we can do for many is "more than 1" and some people would even disagree with that (some interpretations equate "many" and "some").

"Few" is even more ambiguous - it has no specific meaning and can be used in different ways.

For example:

"A few people I know like cheese" would likely mean "at least two ... ".

"Few people like pizza with anchovies" means "not that many people like pizza with anchovies", but has no specific number attached, so the best we could do is "not everyone" or "fewer than all people".

The good news is that "few" rarely appears in a context in which we need to be able to translate.

If you could post some specific examples in which you needed to know the difference (most likely from inference questions), I'd be happy to explain them.

Stuart Kovinsky wrote:"Many" does NOT mean "most". The best we can do for many is "more than 1" and some people would even disagree with that (some interpretations equate "many" and "some").

"Few" is even more ambiguous - it has no specific meaning and can be used in different ways.

For example:

"A few people I know like cheese" would likely mean "at least two ... ".

"Few people like pizza with anchovies" means "not that many people like pizza with anchovies", but has no specific number attached, so the best we could do is "not everyone" or "fewer than all people".

The good news is that "few" rarely appears in a context in which we need to be able to translate.

If you could post some specific examples in which you needed to know the difference (most likely from inference questions), I'd be happy to explain them.

Hi Staurt,

Thanks for the explanation. At this moment I don't have any specific example related to CR, however If I come across any example while studying CR I will definitely take your help. Just started studying CR three days before and struck the above words which confused me because I didnt knew what they mean in context of LR.

Thanks and regards,
Enjoystar

Stuart,
Came across this question on a different gmat forum(gmatclub.com).

In two months, the legal minimum wage in the country of Kirlandia will increase
from five Kirlandic dollars(KD5.00) Per hour to KD5.50 per hour. Opponents of
this increase have argued that the resulting rise in wages will drive the inflation
rate up. In fact its impact on wages will probably be negligible, since only a
very small proportion of all Kirfandic workers are currently receiving less than
KD5.50 per hour.
Which of the following, if true, most seriously weakens the argument?
A. Most people in kirlandia who are currently earning the minimum wage have
been employed at their current jobs for less than a year.
B. Some firms in Kirlandia have paid workers considerably less than KD5.00
per hour, in violation of kirlandic employment regulations.
C. Many businesses hire trainees at or near the minimum wage but must
reward trained workers by keeping their paylevels above the pay level
of trainees.
D. The greatest growth in Kirlandia’s economy in recent years has been in
those sectors where workers earn wages that tend to be much higher
than the minimum wage.
E The current minimum wage is insufficient for a worker holding only one job
to earn enough to support a family ,even when working full time at that job


OA: B but the user posts point to C


Here what is the distinction between some and many i.e which is a superset of which? Also how would u approach the 2 choices?

Would it be C since some is alteast 1 (1-100) but many means more than 1 from what u have said above? I am trying to understand the significance of these 2 words when they appear in answer choices.



Regards,
CR

I will just try to put my thoughts here:

I will go with C, not because of "many" and "some"
even if i had "some" in C, I would have chosen C because of the following reason:

B says that there is already a violation of kirlandic employment regulations. So what is the gaurentee that they would follow new regulations.

Please post your comments.

If (b) is the official answer, then never trust questions from this source again - (b) is definitely not a weakener.

As Jatinder notes, if anything (b) actually (minimally) strengthens the argument, since the author's point is that the higher minimum wage will have little impact on the economy, and (b) says that some companies ignore the minimum wage law entirely. If companies ignore it, who cares what the new minimum wage is?

(c) is correct because it's the only choice that makes us think that a higher minimum wage affects not only minimum wage earners, but also higher paid employees. So, even though it may be true that not many people earn minimum wage, bumping up the minimum wage could lead to an increase in other wages as well.

As for many vs some, I have never seen this issue arise on the GMAT. The problem with using LSAT materials to study for the GMAT is that the LSAT is a very different exam and logical reasoning is NOT always comparable to critical reasoning. Relevant to this thread, the LSAT frequently tests formal logic, the area in which some/many/most/all/etc... need to be understood.

On the LSAT, some = many, i.e. they both mean "at least one". On the GMAT, I wouldn't worry about the distinction; instead, focus on the scope of the argument and look for the choice that's most relevant.

Stuart Kovinsky wrote:If (b) is the official answer, then never trust questions from this source again - (b) is definitely not a weakener.

As Jatinder notes, if anything (b) actually (minimally) strengthens the argument, since the author's point is that the higher minimum wage will have little impact on the economy, and (b) says that some companies ignore the minimum wage law entirely. If companies ignore it, who cares what the new minimum wage is?

(c) is correct because it's the only choice that makes us think that a higher minimum wage affects not only minimum wage earners, but also higher paid employees. So, even though it may be true that not many people earn minimum wage, bumping up the minimum wage could lead to an increase in other wages as well.

As for many vs some, I have never seen this issue arise on the GMAT. The problem with using LSAT materials to study for the GMAT is that the LSAT is a very different exam and logical reasoning is NOT always comparable to critical reasoning. Relevant to this thread, the LSAT frequently tests formal logic, the area in which some/many/most/all/etc... need to be understood.

On the LSAT, some = many, i.e. they both mean "at least one". On the GMAT, I wouldn't worry about the distinction; instead, focus on the scope of the argument and look for the choice that's most relevant.

Hi Stuart.

I am not clear on the reasons for why option C is correct and B is wrong?

Please explain a bit more on this

cramya wrote:Stuart,
Came across this question on a different gmat forum(gmatclub.com).

In two months, the legal minimum wage in the country of Kirlandia will increase
from five Kirlandic dollars(KD5.00) Per hour to KD5.50 per hour. Opponents of
this increase have argued that the resulting rise in wages will drive the inflation
rate up. In fact its impact on wages will probably be negligible, since only a
very small proportion of all Kirfandic workers are currently receiving less than
KD5.50 per hour.
Which of the following, if true, most seriously weakens the argument?

B. Some firms in Kirlandia have paid workers considerably less than KD5.00
per hour, in violation of kirlandic employment regulations.

OA: B but the user posts point to C

I agree that B should not be the correct answer. The word some can mean as few as one. In answer choice B, let's replace the word some with the word one.

One firm in Kirlandia has paid workers considerably less than KD5.00
per hour, in violation of kirlandic employment regulations.

How would this one firm seriously weaken the conclusion?

When you're answering a weaken or strengthen question, be skeptical of answer choices that include the word some.

Since some can mean only one, an answer choice that includes the word some often will not weaken or strengthen the conclusion enough.

GMATGuruNY wrote:

cramya wrote:Stuart,
Came across this question on a different gmat forum(gmatclub.com).

In two months, the legal minimum wage in the country of Kirlandia will increase
from five Kirlandic dollars(KD5.00) Per hour to KD5.50 per hour. Opponents of
this increase have argued that the resulting rise in wages will drive the inflation
rate up. In fact its impact on wages will probably be negligible, since only a
very small proportion of all Kirfandic workers are currently receiving less than
KD5.50 per hour.
Which of the following, if true, most seriously weakens the argument?

B. Some firms in Kirlandia have paid workers considerably less than KD5.00
per hour, in violation of kirlandic employment regulations.

OA: B but the user posts point to C

I agree that B should not be the correct answer. The word some can mean as few as one. In answer choice B, let's replace the word some with the word one.

One firm in Kirlandia has paid workers considerably less than KD5.00
per hour, in violation of kirlandic employment regulations.

How would this one firm seriously weaken the conclusion?

When you're answering a weaken or strengthen question, be skeptical of answer choices that include the word some.

Since some can mean only one, an answer choice that includes the word some often will not weaken or strengthen the conclusion enough.

Hi Mitch
Whats wrong with Option E ?

Stuart Kovinsky wrote:If (b) is the official answer, then never trust questions from this source again - (b) is definitely not a weakener.

As Jatinder notes, if anything (b) actually (minimally) strengthens the argument, since the author's point is that the higher minimum wage will have little impact on the economy, and (b) says that some companies ignore the minimum wage law entirely. If companies ignore it, who cares what the new minimum wage is?

(c) is correct because it's the only choice that makes us think that a higher minimum wage affects not only minimum wage earners, but also higher paid employees. So, even though it may be true that not many people earn minimum wage, bumping up the minimum wage could lead to an increase in other wages as well.

As for many vs some, I have never seen this issue arise on the GMAT. The problem with using LSAT materials to study for the GMAT is that the LSAT is a very different exam and logical reasoning is NOT always comparable to critical reasoning. Relevant to this thread, the LSAT frequently tests formal logic, the area in which some/many/most/all/etc... need to be understood.

On the LSAT, some = many, i.e. they both mean "at least one". On the GMAT, I wouldn't worry about the distinction; instead, focus on the scope of the argument and look for the choice that's most relevant.

Stuart,

I understood your reasoning. But i have a doubt here.

B says some, it could be as least 1 or anything from 1 to 49 %.

Now C says

Many businesses hire trainees at or near the minimum wage but must
reward trained workers by keeping their paylevels above the pay level
of trainees.

There is an indicator OR.

All of these MANY trainees can either exactly at 5 dollar (minimum) or below 5 dollar.

If all of these many, a possibility, are exactly 5 dollar then the statement would not weaken the argument at all as argument says that the proportion of workers who get LESS that minimum.

So from C, can we say surely that majority of these MANY people are earning LESS than 5 dollar.

C can produce trivial answers.