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#10 - Those who have the ability to fully concentrate are

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Complete Question Explanation

Cannot Be True—SN. The correct answer choice is (A)

This stimulus provides several conditional statements:

If one has the ability to fully concentrate, one is above average intelligence:

    Ability to fully concentrate ..... :arrow: ..... above average intelligence

Also, getting successfully trained in speed reading is usually accompanied by an increased ability to concentrate (notice that this vague increase does not equate to the ability to “fully” concentrate).

    Successful speed reading ..... :arrow: ..... usually increased ability to concentrate

The question stem tells us that all of the answer choices could be true except one. Thus, the correct answer choice will be the one that cannot be true.

Only correct answer choice (A) is precluded based on the conditional statements above. Since we know from the stimulus’ first conditional statement that everyone who can fully concentrate is above average intelligence, there can’t be anyone who can fully concentrate who is below average intelligence. None of the other answer choices are contrary to the sufficient-necessary statements above.
a.lsat
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Hello PowerScore

I think this one is a Formal Logic Question, yet find myself stuck in it.

This is how I approach the stimulus:
Premises1: Full concentration :arrow: Above-average intelligence
Premises2: Speed reading :most: Increased ability to concentrate
Combined: Speed reading :most: Concentrate :arrow: Above-average intelligence
Is that correct?

Also, do you think “having the ability to fully concentrate” is equivalent to “increased ability to concentrate?” I'm actually quite confused with it.

--

Since the question stem indicates that it's a CouldBeTrueX Question,or CannotBeTrue Question, I only contended answer choice (B) and (E); eliminated the rest, finding the language usage in both choices too strong.
("All" in the answer choice (B)/(E), compared to "always/usually" in the stimulus.)

(B) Speed reading :arrow: Above-average intelligence
(E) Speed reading :some: Concentrate

Inference in answer choice (E) sound valid if examined with The Logic Ladder, yet the inference in answer choice (B) is invalid. I choose (B) as the question stem requires the one CannotBeTrue.

Yet the correct answer choice is neither (B) nor (E)!

--

Can you help me find out the flaw in my reasoning if there's any and demonstrate, with formal logic, how to get the correct answer? Thanks!
David Boyle
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a.lsat wrote:Hello PowerScore

I think this one is a Formal Logic Question, yet find myself stuck in it.

This is how I approach the stimulus:
Premises1: Full concentration :arrow: Above-average intelligence
Premises2: Speed reading :most: Increased ability to concentrate
Combined: Speed reading :most: Concentrate :arrow: Above-average intelligence
Is that correct?

Also, do you think “having the ability to fully concentrate” is equivalent to “increased ability to concentrate?” I'm actually quite confused with it.

--

Since the question stem indicates that it's a CouldBeTrueX Question,or CannotBeTrue Question, I only contended answer choice (B) and (E); eliminated the rest, finding the language usage in both choices too strong.
("All" in the answer choice (B)/(E), compared to "always/usually" in the stimulus.)

(B) Speed reading :arrow: Above-average intelligence
(E) Speed reading :some: Concentrate

Inference in answer choice (E) sound valid if examined with The Logic Ladder, yet the inference in answer choice (B) is invalid. I choose (B) as the question stem requires the one CannotBeTrue.

Yet the correct answer choice is neither (B) nor (E)!

--

Can you help me find out the flaw in my reasoning if there's any and demonstrate, with formal logic, how to get the correct answer? Thanks!


Hello a.lsat,

There may be aspects of formal logic here, though I may focus on other things as well.
"Also, do you think “having the ability to fully concentrate” is equivalent to “increased ability to concentrate?”" you ask above. No, I think they are different, so this is sort of a trick question. So the chain you made above, linking all three together, is not valid, unfortunately.
And for that reason, answer B is not a problem. It's not true that only some ("most") speed-readers could be of above-average intelligence. Maybe they all are, so answer B is o.k.
Answer A, "Some people can speed-read, and are able to fully concentrate, but are of below-average intelligence", by contrast, directly contradicts the stimulus, which says full concentration means above-average intelligence.
(Also, you say "(E) Speed reading :some: Concentrate". I'm not sure that's right, though; your diagram says that there's merely some overlap between speed reading and concentrating, but answer E really means that all speed readers can concentrate some. Speed reading :arrow: some concentration.)

Hope this helps,
David