Q10 - Those who have the ability

[sarahhaque]

Hi,

For the inference question, "Those who have the ability to fully concentrate....."

I'm having trouble understanding why answer choice A must be false compared to the other answer choices. I seem to get thrown off when the LSAT uses words like "some, all, many..." in the answer choices

Thanks!

[ManhattanPrepLSAT1]

This question poses some unique challenges.

We know that everyone who has the ability to fully concentrate are always of above average intelligence. Answer choice (A) says that some people who have the ability to fully concentrate are of below average intelligence. Yes, the test writer also included something about these people being able to speed read, but that does not change the fact that answer choice (A) has people who are able to fully concentrate but who are not of above average intelligence. We know this cannot be true.

There are two statements contained in the stimulus.

1. Those who have the ability to fully concentrate are always of above average intelligence.
2. Most people who can speed read have an increased ability to concentrate.

We need to find an answer that contradicts one of these statements.

(A) contradicts the first statement for the reasons above.
(B) could be true. We know that those who can speed read usually have an increased ability to concentrate. Maybe they could also have above average intelligence. We can't prove (B) to be true, but we can't prove it false.
(C) must be true. If everyone who has the ability to fully concentrate has above average intelligence, then some with above average intelligence must have the ability to fully concentrate.
(D) is not discussed. This could be true, it could be false, who knows!
(E) could be true. We know that most people who can speed read have an increased ability to concentrate. We are not sure, however, about those others who can speed read. We don't know that they have the ability to concentrate to some extent, but we don't know that they don't either!

[robowarren]

Hi,

I got the answer right, but I am working on my conditional logic diagramming skills. Would you mind posting the logic diagrammed? This is what I did:

C --> I
SR --> C

SO

SR --> C --> I

Is that right?

Thank you!

[timmydoeslsat]

Hi,

I got the answer right, but I am working on my conditional logic diagramming skills. Would you mind posting the logic diagrammed? This is what I did:

C --> I
SR --> C

SO

SR --> C --> I

I am glad you got this right, but we are going to fix some things if I have my way!

I would diagram the two statements like this:

Ability to full concentrate ---> Above avg intel

Successfully trained speed reading MOST Increased ability to concentrate

These two statements cannot be combined.

Also notice that where you have "C"...the stimulus tells us "ability to fully concentrate." You may misread this during the test as concentrate. We only know of an ability, not necessarily having concentrating occur.

It did not come back to bite you on this question, but it can happen.

Also, ability to fully concentrate is not the same as "increased ability to concentrate"...so we cannot have that be denoted the same.

Do not be afraid to write some short hand instead of acronyms. To me, it takes longer trying to interpret the acronyms than to actually do a couple of words in my conditionals.

I will bring back what we know from this stimulus:

Ability to full concentrate ---> Above avg intel

Successfully trained speed reading MOST Increased ability to concentrate


We know that A must be false. It states that some people that have ability to fully concentrate are ~Above avg intel, and this is in direct contradiction to what we know as fact.

[slimz89]

Can you please diagram answer C?

With my diagram of answer choice C it came out like this:

Many above--->~fully concentrate
Contrapositive- fully concentrate--->~many above

Doesn't this contradict the stimulus?

Fully concentrate---->above intelligence

[ManhattanPrepLSAT1]

Hey slimz89, the issue here is that you're taking a contrapositive of a "some" statement. Unfortunately there is no contrapositive of a "some" statement.

You can notate the stimulus:

FC --> AAI
SR -most-> IAC

Answer choice (C) looks like:

AAI <-some-> ~FC

This doesn't contradict either of the original statements. To contradict the first statement you would need FC <-some-> ~AAI.

Hope that helps!

[crazyapple11]

Hi, I am a little confused about the meaning of "always". The first sentence says "those who...are always of above-average intelligence". My understanding is that it means someone may not be of above-average intelligence. Otherwise, the author could just say "are of " without "always." Please help. Thank you.

[ManhattanPrepLSAT1]

Tricky one!

Take the following two examples...

1. Red cars are faster than blue cars.
2. Red cars are always faster than blue cars.

On the LSAT, there's no difference in meaning. According to either statement, it's not possible for some blue cars to be faster than some red cars -- red cars are always faster.

Hope that helps!

[crazyapple11]

It helps a lot! Thank you so much.

[LeylaM314]

How come answer C must be true if it says that many people of above-average intelligence are unable to fully concetrate. Can somebody explain it please?