#10 - The Asian elephant walks with at least two, and

[mokkyukkyu]

It doesnt talk about one leg, but it's just common sense right?
Just wanted to double check...

[Nikki Siclunov]

Hi mokkyukkyu,

Thanks for your question.

The stimulus is structured as follows:

• Premise: Elephant always has at least 2 legs on the ground.
  Conclusion: Elephant does not run.

To justify the conclusion, we need to establish the following:

• Justify: At least 2 legs on the ground NOT run
  Contrapositive: Run Less than two legs on the ground

The correct answer choice (B) goes even further, suggesting that running requires the animal to have all four legs off the ground:

• Answer choice (B): Run NO legs on the ground
  Contrapositive: Any legs on the ground NOT run

There is no problem with this, because we are looking for a premise that is sufficient to prove the conclusion, not an assumption necessary for the conclusion to be logically valid. Yes, answer choice (B) goes beyond the scope of our prephrase, but so what? If answer choice (B) is true, then clearly an animal that has at least one leg on the ground at any given time cannot run. The elephant falls into that category of animals, because it has at least two legs on the ground at any given time. So, it logically follows that the elephant cannot run.

Thanks!

[stephodigie]

Could someone explain why E would not be correct? I am still very confused with this problem

[Malila Robinson]

Hi stephodigie,
Answer E talks about other animals feet in relation to walking, but the "hole" in the argument relates to how many feet you need to have on/off the ground in order to qualify as running. Since E does not address feet in relation to running it cannot be the correct answer.
Hope that helps!
-Malila

[hoyasaxa21]

Good morning!

Could someone please explain why answer choices (A), (C), and (D) are incorrect?

Thank you very much, and have a great day!

Chris

[Jeremy Press]

Hi Chris,

At the very most basic, answer choices (A), (C), and (D) do not prove (i.e. "Justify") the conclusion and so they don't satisfy the standard the question stem asks for. Below is a little more on why.

Answer Choice A: This answer has the wrong sufficient condition to prove that the Asian elephant cannot run. Our Asian elephant (from the premises) CAN accelerate. So this answer simply doesn't apply to the Asian elephant, and can't prove that it can't run.

Answer Choice C: This answer is irrelevant to the conclusion. Whether or not the Asian elephant's walking speed is the same as (or faster than) some animals' running speed doesn't tell us whether the elephant has the ability to run. It just means that the elephant is a relatively fast walker! Those Olympic speed-walkers aren't running, yet some of them are walking faster than my typical running speed (which is quite slow!). That doesn't prove the speed-walkers can't run--it just proves they're pretty fast at walking.

Answer Choice D: This answer is irrelevant to the conclusion. How common (or usual) it is in the animal world to have three feet on the ground while walking doesn't really tell us anything about those animals' (particularly the Asian elephant's) ability to run. It just tells us what they usually do when walking.

Hope this helps!

[gingerale]

If there was an answer choice that provided that taking quicker and longer steps does not qualify as running, could this also be correct?

[Adam Tyson]

In my view, gingerale, no, that wouldn't be enough to justify this conclusion, although it would strengthen it by a lot. The problem with such an answer would be that it would fail to account for other things that might count as running. What if, for example, moving with two feet on the ground but NOT accelerating might be considered running? What if "running" could include moving at a constant pace over a long period of time? A stretch, I know, but we need to account for those sorts of outliers if we want to truly justify a conclusion. We are looking for total, absolute proof that eliminates any exceptions.

That said, your proposed answer would be the right answer IF there was no better choice (like answer B) available, because we are supposed to select the best answer even if it may be slightly imperfect.

[2024W]

Doesn't the fact that it says "at least two" suggest that it could have four (at most) on the ground at all times, and thus be able to run? The stimulus never said that it NEVER has all four on the ground.

[Rachael Wilkenfeld]

Remember the question type here, 2024. It's a justify question, so we are trying to prove that it DOESN'T run. To do so, we need to connect the premises to the conclusion. Answer choice (B) tells us that it can't have any feet on the ground and be running. The elephant always has at least two feet on the ground. Therefore when we add that running requires all feet off the ground, we know it's incompatible with running, thus proving the conclusion.

Hope that helps!