CR: In general, jobs are harder to get in times of economic

[RonPurewal]

choice C has no effect, because the restriction on student/teacher ratios is based only on CURRENT numbers of students and teachers.

previous numbers are irrelevant, because we are concerned only with
• restrictions based on CURRENT numbers of teachers and students,
• how those restrictions will affect FUTURE numbers of teaching jobs.

past numbers don't figure into either of these, so, past numbers are immaterial here.

[RonPurewal]

Additionally "Option C" I know is not a strengthener, but is it a potential weakener?

it's a waste of your time to consider this, because, for the purposes of this problem, that's a non-distinction.

the problem is to find a strengthener.
thus, there is only one distinction with any meaning here: "yes, strengthener" vs. "no, not a strengthener".
both of those possibilities fall under "no, not a strengthener"... so there's no reason to try to distinguish them.

[RonPurewal]

it's actually VERY important that you not distract yourself in this sort of way.

If the problem is "strengthen", then there will be ...
... 1 answer choice that strengthens the argument,
... 4 answer choices that don't strengthen the argument.
among those 4 choices, there COULD be -- and often are -- choices that "might weaken, might do nothing". that's fine, because they still clearly DON'T STRENGTHEN the argument -- and that's all you care about.

similarly, if the problem is "weaken", then there will be ...
... 1 answer choice that weakens the argument,
... 4 answer choices that don't weaken the argument.
among those 4 choices, there COULD be -- and often are -- choices that "might strengthen, might do nothing". that's fine, because they still clearly DON'T WEAKEN the argument -- and, again, that's the only goal of the problem.

[JustinCKN]

The new law says that the student/teacher ratio can't increase.
Therefore:

"- High student/teacher ratios are not a problem at all.
In fact, if the ratio is at the maximum value and more students join, then more teachers will be needed.

"- If student/teacher ratios are lower, THEN teachers might lose their jobs without a violation of the cited law.

So:
An answer choice that suggests that ratios might increase"”or WON'T decrease"”will strengthen the argument.

Choice A suggests that the ratio is already abnormally high for a recession. Therefore, in choice A, the ratio is more likely to decrease than to increase further.
(Analogy: If you know that it's unusually hot for a June day today, then the weather is much more likely to cool off than to get even hotter!)

Choice B suggests that there will be a significant influx of (former) private-school students when the economy goes sour"”essentially guaranteeing that the ratio won't decrease.

Hi dear instructor RON
According to your reasoning,in choice A, the ratio is more likely to decrease than to increase further, then the choice A will support the conclusion.
For example. Current student-teacher Ratio=100(students):1(teacher) . if the Ratio decrease to 50(students):1(teacher) and the total number of students remain the same. then we need more teachers. -> strengthen the argument.
what's wrong in my reasoning?

OR from another aspect ,I think that A is wrong because the argument cares about the future,but A just provide the information about the current and past.
Thanks advanced.
JustinCKN.

[RonPurewal]

A is wrong because the argument cares about the future,but A just provide the information about the current and past.

^^ precisely that.

[RichaChampion]

Thanks JustinC523 and Ron sir.

[JustinCKN]

A is wrong because the argument cares about the future,but A just provide the information about the current and past.

^^ precisely that.

HI.Ron:
Thanks for your confirmation!
sincerely!
JustinCKN.

[JustinCKN]

Thanks JustinC523 and Ron sir.

No thanks.

[RonPurewal]

if anyone has any further questions, please post.

[RichaChampion]

sunny's explanation is good.

i'll get to the main point:

you see the following words:
and that current student-teacher ratios not be exceeded.

this means that, if you add more students, you HAVE to add more teachers. if you don't get rid of students, you CAN'T get rid of teachers.

therefore, any choice that implies that you won't lose students, or you'll even gain students, will be a HUGE strengthener.

this is what (b) does. it strongly suggests that the public schools will see an influx of students who used to attend private school but can't afford it anymore.

Which of the following, if true, most strengthens the argument?
A. The current student-teacher ratio at Vargonia's government-funded schools is higher than it was during the most recent period of economic recession.
B. During recent periods when the Vargonian economy has been strong, almost 25 percent of Vargonian children have attended privately funded schools, many of which charge substantial fees.
C. Nearly 20 percent more teachers are currently employed in Vargonia's government-funded schools than had been employed in those schools in the period before the last economic recession.
D. Teachers in Vargonia's government-funded schools are well paid about teachers in most privately funded schools in Vargonia, many of which rely heavily on part-time teachers.
E. During the last economic recession in Vargonia, the government permanently closed some the schools that it had funded

[/quote]

Ron sir, I have seen that many time in CR questions GMAC creates two options that are almost same, but worded differently.

I have affirmation that option A and option C are one and the same option, but worded differently and therefore, none of them can be a correct option because in GMAT CR two options can't be simultaneously correct. In many CR questions, I can eliminate two options without any ambiguity. This is not always or mostly applicable, but sometimes it is applicable as in this question.

[RonPurewal]

you may want to go back and read those choices again. they're definitely NOT equivalent. in fact, they are much closer to being exact opposites.
(increasing the number of teachers actually makes the student/teacher ratio smaller)