Critical Reasoning

Source: MGMAT cat

Everyone who has graduated from TopNotch High School has an intelligence quotient (IQ) of over 120. Most students with an IQ of over 120 and all students with an IQ of over 150 who apply to one or more Ivy League universities are accepted to at least one of them.

The statements above, if true, best support which of the following conclusions?

A: Every graduate of TopNotch High School with an IQ of 150 has been accepted to at least one Ivy-League school.
B: If a person is a high-school graduate and has an IQ of less than 100, he or she could not have been a student at TopNotch High School.
C: If a person has an IQ of 130 and is attending an Ivy-League school, it is possible for him or her to have graduated from TopNotch High School.
D: At least one graduate from TopNotch high school who has applied to at least one Ivy-League university has been accepted to one of them.
E: If a high-school graduate has an IQ of 150 and is not attending an Ivy-League school, then he or she did not apply to one of them.

OA:C

My question is - I took > 5 minutes and still got it wrong. I got the answer later on. But, i havent seen such CRs in OG

Voodoo

Hi, there's nothing wrong with the design of the question as such, it's just that it is quite technical involving formal logic principles that are more likely to be tested on the LSAT not the GMAT.

Anyhow, if you want to improve in inference questions--if you want to have been able to get this question right the first time, and not just right, but quickly--then, one technique you should train yourself to use is the Kaplan Denial Test.

Applied to choice C:

If choice C were false--if it were IMPOSSIBLE for for a 130IQ, Ivy-league attender to have come from TopNotch, would the passage still make sense? Or would it conflict with the passage?...

If you judge that falsifying choice C would also falsify the passage (either in part or the whole passage), then you know that choice C must be true since we're not allowed to falsify the passage in inference questions (the question stem reads "The statements above, IF TRUE,...").

thanks. if you dont mind, can u pls tell me what's denial test? thanks in advance.....

voodoo_child wrote:thanks. if you dont mind, can u pls tell me what's denial test? thanks in advance.....

The denial test is a way of verifying whether something must be true. In the question above I applied the test to answer choice C: If you DENY choice C (i.e., if choice C were false), then the passage becomes false. Thus, choice must be true.

You can also use the denial test in assumption questions. For example, suppose the question is:

"which of the following is an assumption upon which the argument depends?"

And let's say the argument itself can be summed up like this:

"The author argues that the tasmanian tiger is extinct because there is no evidence of their survival in their natural habitat."

and suppose an answer choice said this:

"The Tasmanian tiger did not move out of its natural habitat."

Does the argument DEPEND on this answer choice? In other words does this answer choice HAVE TO BE TRUE in order for the argument to hold? Well, if we deny the choice we would have:

"The Tasmanian tiger DID move out of its natural habitat."

in which case the argument that the tiger is extinct no longer holds any water. So, when we DENY this answer choice, the argument fails. Thus, the argument depends on that answer choice, and it is correct.

Let me know if that's clear. I've applied the denial test several times in previous posts, so I can dig some up if you'd like.