Critical Reasoning

Brian@VeritasPrep wrote:Hey paes,

I think you're right with what you wrote...but in doing so you omitted what is probably the most important part of answer choice B.

The correct answer in Inference ("find the conclusion") questions MUST BE TRUE. One way that the GMAT can accomplish this logical certainty is by offering an if/then statement that involves complementary events (one of them must happen).

Consider this example:

"If I apply to Harvard Business School and am not rejected or waitlisted, I must be admitted to HBS."

This sentence does not simply say "I must be admitted to HBS" (as lovely a sentiment as that would be). It qualifies it by saying "unless the other two possible outcomes happen, the third will". That statement, then, must be true - if only three things can happen, and the statement qualifies the other two, then it's true.

Answer choice B in this sentence does essentially the same thing:

If the U.S. does not find ways to replenish the soil (which we know from the passage is eroding faster than it builds up) it must eventually find new ways of getting agricultural products.

That essentially says: the soil is eroding faster than it builds up, so unless we can reverse that trend, the soil will be gone eventually and the current soil-based methods of agriculture will no longer work.

That's true.

When an answer must be true, look for sentences that are all-encompassing like this one and therefore ensure their own logical certainty. For another good example, you may want to view this post:

Question: https://www.beatthegmat.com/mba/2010/06/ ... nd-algebra

Solution: https://www.beatthegmat.com/mba/2010/06/ ... d-geometry[/list]

SmarpanGamt wrote:
I have a doubt

In real GMAT senario , the question stem will be

1. If the above statement is true , Which of the following is best supported by the information above?

OR

2 .If the below statements are true , Which of the following is best supported by the information above?

I believe in Position 1 , the OA could be B , Since no other / external information is allowed to support the argument. ( Inferences problem )

And in the case of Position 2 , the OA should be A

David@VeritasPrep wrote:

SmarpanGamt wrote:
I have a doubt

In real GMAT senario , the question stem will be

1. If the above statement is true , Which of the following is best supported by the information above?

OR

2 .If the below statements are true , Which of the following is best supported by the information above?

I believe in Position 1 , the OA could be B , Since no other / external information is allowed to support the argument. ( Inferences problem )

And in the case of Position 2 , the OA should be A

SmarpanGamt - you are saying that so long as this is an inference question that B is correct. But you do not feel that it is easy to identify that it is an inference question from the stem.

Your first formulation is ONE possible way to say that you have an inference question. In fact, on the GMAT the most common way to recognize the inference question is the phrase "Which of the following conclusions..."

Look through the Official Guide and see that this is true.

As for this particular question, originally it said,
"Which of the following conclusions is best supported by the information above?"

We took out the word "conclusion" in order to help students practice identifying the tougher stems.

There is another reason that this question cannot be a strengthen -- it has no conclusion in the stimulus!!

Re-read this stimulus. It is called a "set of facts" because there is no conclusion, just several premises. When you find that a stimulus has no conclusion it cannot be a strengthen or weaken but it can be an inference.

SmarpanGamt - what you cite as the conclusion is only another premise. It is stated in the stimulus that 16% use no- till. But if you use the "why?" test you will find that this cannot be the conclusion because there is no premise that is supporting it. What I mean is ask "why do only 16% use no-till?" There is nothing in the stimulus to answer this. When something is simply stated as a fact and does not rely on any other premise it is not a conclusion.