Those who have the ability to fully concentrate are always of above–average intelligence. Also, being successfully tr...

Victoria on May 30, 2021

Hi @lklop,

Happy to help!

This question is definitely a bit confusing. What is important to note is that the question stem asks us to identify the answer choice which 100% cannot be true based on the information provided in the stimulus. This means that all of the incorrect answer choices could possibly be true; it does not mean that we have to prove that they must be true based on the stimulus. We are focused on finding the answer choice which absolutely contradicts the information we are provided with.

The stimulus tells us that "those who have the ability to fully concentrate are always of above-average intelligence." In other words, if you have the ability to fully concentrate, then you are of above-average intelligence.

Ability to fully concentrate --> Above-average intelligence
Not above-average intelligence --> Do not have ability to fully concentrate

We also learn that "being successfully trained in speed-reading will usually be accompanied by an increased ability to concentrate."

Trained in speed-reading - most - Increased ability to concentrate
Increased ability to concentrate - some - Trained in speed-reading

Unfortunately, we cannot combine any of the above statements to draw any further conclusions due to the shift in terms. But let's go through our answer choices.

Answer choice (B): "all people who can speed-read are of above-average intelligence."

This could be true. We do not have any information on the relationship between speed-reading and intelligence; therefore, we cannot prove that it is true, but we also cannot prove that it cannot be true.

Answer choice (C): "many people of above-average intelligence are unable to fully concentrate."

We know from our diagram above that, if you can fully concentrate, then you have above-average intelligence. We also learn that, if you do not have above-average intelligence, then you cannot fully concentrate. However, we do not have enough information to disprove the claim that many people of above-average intelligence cannot fully concentrate. Therefore, this could be true.

Answer choice (D): "some people with little ability to concentrate are of below-average intelligence but can speed-read."

Again, we do not have enough information to disprove this. We know that most people who are trained in speed-reading have an increased ability to concentrate, but we do not know the relationship between the three variables (i.e. intelligence, ability to concentrate, and ability to speed-read).

Answer choice (E): "all people who can speed-read are able to concentrate to some extent."

This makes sense from a common sense perspective as it seems likely that speed-reading requires at least some level of concentration. Again, we can eliminate this answer choice because we do not have enough information to disprove it.

Answer choice (A) is incorrect because it contradicts the first sentence in the stimulus. We know that, if you are able to fully concentrate, then you have above-average intelligence. Therefore, it cannot be true that some people who can fully concentrate are of below-average intelligence.

Hope this helps! Please let us know if you have any further questions.