Knewton Challenge: Win Knewton Shirt and GMAT Club Tests

Evidences stated in the argument:

1. Joey is born after short gestation period
2. Joey's hind limbs are not well developed, but its forelimbs are.
3. The purpose of (2) is so it can climb into mother's pouch
4. Marsupial lions were born with only forelimbs developed

Argument implies:
"only lion's forelimbs were developed" ==> (implies) further development needed

Conclusion:
Hypothesis that newborn marsupial lions must have needed to climb into mother's pouches.

Answers: [E]

A. Nothing is mentioned about the gestation period of lion; We dont know if it is short or long. So "all animals" are born after short gestation period is not valid.

B. Nothing mentioned about the usage of hind limbs vs. forelimbs of lion in premises.

C. No discussion about paleontologist in the passage.

D. That newborn lions climbed into mother's pouches is conclusion. They had forelimbs developed at birth is evidence.There is no assumption in this answer choice.

E. This connects the evidence of developed forelimbs of joey with that of lion and ties to the conclusion that lions used these forelimbs to climb into mother's pouches. The assumption here is "what is the use of developed forelimbs if not needed to climb into mother's pouch". Hence this is the correct answer.

Hi its D

Because in D it is clearly mentioned that if the Kangarro did not develop forelimbs then it wouldn't have climb to mother's pouch....But in the paragraph it is mentioned that the kangaroo which has forelimbs developed will be able to climb to mother's pouch..

So i will go with D

The answer is "B".
Premise 1. A newborn kangaroo, or joey, is born after a short gestation period of only 39 days.

Premise 2. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development.

Premise 3. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed

Conclusion 1. The newborn marsupial lions must also have needed to climb into their mothers’ pouches

As concluded, the newborn marsupial lions must also have needed to climb into their mothers' pouches.....no problem so far.....but why premise 3. will support conclusion 1.
Premise 3. will only support conclusion if Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been.

hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.-

- Asumptions must connect the dots between developed forelimbs at birth and the need to climb into mothers’ pouches. Now lets scan the answers one by one:

A- Way to general-use of "All". moreever some underdeveloped parts for all animals do not help us in connecting the dots!
B- It does not matter to us in the given context the advantage of developed forelimbs over developed hind. Again it does not help us to connect the equation as mentioned above.
C-Again a non consequential answer- finding evidence by paleontologists is not much of use to fill the gap in reasoning that how does developed forelimbs must have been in order to help marsupial lions to climb into their mothers’ pouches.
D- Seems all right and fills the gap in the reasoning - this shows that developed forelimbs at the time of birth was essential to the Newborn marsupial lions to crawl into their mothers’ pouches and without their developed forelimbs at birth it would not have been possible for the Newborns to crawl into their mothers’ pouches.
E-Nothing wrong with this answer, infact second best answer. D is better than E, because E is too general in emphasizing the use of developed forelimbs at birth. We are not discussing about "any use" but whether developed forelimbs -> requirement of crawling into mother's pouches!

Retrospecting all the above choices- A, B, and C were not at all addressing the issue at hand. It was a close call between D and E, but since D gives specific use of developed forelimbs: I would pick D over E.

The answer is a close call between B and E. But i will go with asnwer choice E. The premise for the conclusion is that at birth the lions had developed forelimbs just as the kangaroo had at birth. So the lions must also use the forelimbs to climb into their mother's pouches. The argument assumes that it cannot be possible for the forelimbs to be developed at birth of lions for no valid reason. It is very much possible that the development could have taken place for no reason at all. Therefore, the argument rests on this assumption.

Correct Answer: (D)

Explanation: The conclusion is that the marsupial lions must have needed to climb their mother's pouch. Lets consider the choices one by one:
(A) For ancient marsupial lions, firstly, it is nowhere mentioned in the argument that they were born after a short gestation period. May be they were born with only fore limbs developed even after a long gestation period. Secondly, we don't need to assume that they were born with some parts underdeveloped as this is mentioned in the argument itself.
(B) Well developed forelimbs could well have been more advantageous than hind limbs to marsupial lions but for what purpose? May be for running but not necessarily for climbing their mother's pouch. Even if we assume that fore limbs were more advantageous, we cannot say that they were more advantageous for the purpose of climbing.
(C) It is clearly mentioned in the argument that it is an hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches. Paleontologists have no way to determine whether the marsupial lions actually did so or not.
(D) Lets assume that marsupial lions were born with their fore limbs AND hind limbs developed. Logically speaking, they must have been equally capable, if not more, of climbing their mother's pouch. But in the argument, the conclusion is based upon the development of ONLY the front limbs. So to reach the conclusion based upon the development of ONLY the front limbs, it is imperative to assume that the development of hind limbs must have reduced the capability of marsupial lions to climb into their mother's pouch.
(E) Again, the development of only the forelimbs could have been due to some purpose use but simply assuming this is not enough to conclude that the purpose was to climb into their mother's pouch.


Desperate for the tests

C is my answer.
If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.since there is no evidence of this fact,the new discovery supports the theory, that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

This is an assumption question. So if one of the statements in answer options is correct stimulus is correct.

New data can appear in answer options.

Premise1:A newborn kangaroo, or joey, is born after a short gestation period of only 39 days.

Premise2 : The joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development.

Conclusion: The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

Assumption:Whatever is developed fully at birth is useful to serve some purpose.

A)Wrong - It generalizes phenomena(Specific to only few animals
B)Wrong - Relative advantages of development of forelimbs or hind limbs are not discussed.
C)Wrong - Paleontologists findings are no where assumed
D)Wrong - They can crawl into mothers pouch even if both fore limbs and hind limbs are fully developed at birth. It cant be that if they have only fore limbs fully developed they can crawl
E) Right - It states the assumption that fully developed forelimbs at the time of birth serves some purpose.

A newborn kangaroo, or joey, is born after a short gestation period of only 39 days. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

The argument in this passage relies on which of the following assumptions?

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped. (Talks about all animals and we do not care about all of them)
[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been. (Talks about what would be better. Moreover, no where in the passage it is told that Well developed forelimbs are better then Well developed hind limbs. We are not comparing those two. The option which we need should refute the analogy mentioned in the passage )
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact. (paleontologists still do not know that whether newborn marsupial lion did climb into its mother’s pouch. The are just guessing by providing the analogy)
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.(marsupial lions that crawled - out of scope)
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions.

IMO:E.

The argument depends on the assumption that if marsupial lions are also born with their forelimbs developed then it's because they need those forelimbs.

And if you will negate option E the argument(conclusion) will fall apart.

A newborn kangaroo, or joey, is born after a short gestation period of only 39 days. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

The argument in this passage relies on which of the following assumptions?

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped.
[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been.
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions.

My answer D

I think the Answer is D.
A. generalizes that all animals born after short gestation period have underdeveloped parts.
B. The paragraph does not provide any relation between forelimb usage and hind limbs.
c. finding evidence is not something explored in the paragraph.
D. only new born with developed forelimbs can crawl into their mother's pouches. expresses the similarity how a marsupial lion was similar to a kangaroo
E. Restrict the development to forelimbs.

I choose E. the assumption that i prephrased was "the lion mother's pouch is the only place where lions can further develop", which was not an answer choice. so I had to dig deeper.

by POE,
A)out of scope, passage does not discuss "all" animals, just kangaroos and marsupial lions
B)goes directly against passage. "the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb ...into its mother’s pouch"
C)out of scope, passage does not mention paleontologists or their findings

now between D/E: it was tough since the logic in the answer choices was so convoluted, but I threw out D.
D)extremely convoluted logic, double negatives. irrelevent information. any further development of the marsupial lion in the gestation period would not have anything to do with it's ability to crawl into the pouch, since the passage states that development of forearms is all that's needed to crawl into pouch.

E)correct choice. assumption lies in the fact that usage of the forearms is for getting into the mother's pouch. By negating this fact, the argument falls apart.

Obviously E. the easy association with the development of forelimbs of lions to jumping to their mother's pouch assumes that forelimbs develop always for a purpose; in this case it was that of jumping to mother's pouch.

Ans E.

If it is assumed that well developed forelimbs are not useful for anything then the conclusion that ancient marsupial lions used those limbs to climb up to their mother's pouch falls apart.

The correct answer is "E. Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions."

Explanation:

The premises are:
"A newborn kangaroo, or joey, is born after a short gestation period of only 39 days."
"The joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development."
"The recent discovery that ancient marsupial lions were also born with only their forelimbs."

The conclusion is:
"Newborn marsupial lions must also have needed to climb into their mothers’ pouches."

The newborn marsupial lions have only forelimbs developed (which MAY allow them to climb into their mothers' pouches) and they would not have had only their forelimbs developed if this development were of no use to the marsupial lions (that means they MUST also have needed to climb into their mothers’ pouches.). The answer choice E create a link to ensure the soundness of the conclusion.

My answer is "E" .. The reasons are as below -

A - Incorrect - nowhere in the passage its said that marsupial lions had a short gestation. So, its good to reject this
answer
B - Incorrect - This is wrong, the comparison what is more advantageous - forlimbs or hindlimbs is not necessary as per the
passage.
C - Incorrect - Out of context. Why should we bother about paleontologists are able to figure out something or not?
D - Incorrect - We are talking about climbing the mother's pouch because of hind legs being developed. Here they talk about
"crawling".
E - Correct - Forelimbs are developed for a purpose and this purpose seems to go well with the hypothesis.

A newborn kangaroo, or joey, is born after a short gestation period of only 39 days. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

The argument in this passage relies on which of the following assumptions?

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped.
Wrong. The passage doesn't talk about all animals
[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been.
Wrong. We don't need to compare forelimbs and hindlimbs
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.
Wrong. Maybe this is true. But again this doesn't concern us as this is a speculation about the future
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
Correct. Passage is about a specific parallel use of forelimbs in Joey and lions. For this parallel to be ture, the states fact, that forelimbs were used to climb into the mother's pouch should also be ture.
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions.
Wrong. The passage talks about a specific use of the forelimb and not just any use