Two different cages of rabbits were given injections of mild toxins. I

Question

Two different cages of rabbits were given injections of mild toxins. In addition, the first cage was also exposed to a cold temperature; three-fourths of the rabbits in this cage became sick. Only one-fifth of the rabbits in the normal temperature cage became sick. The lab technicians concluded that cold temperature increases the likelihood of illness in rabbits. 
The technicians’ conclusion logically depends on which of the following assumptions?

(A) The exposure to the cold temperature acted as a catalyst for the toxins, which made more rabbits in the first cage sick.
(B) The toxins given to the rabbits in the two cages were of the same strength and the same amount.
(C) Injecting the rabbits with toxins does not make them sick.
(D) Even without the exposure to cold temperatures, the rabbits in the first cage would have probably gotten sick.
(E) Even exposing rabbits to slight variances in temperature is likely to induce illness irrespective of which cage the rabbits belong to.

bb · Accepted Answer

FYI - it seems MGMAT has revised the question in the 8th edition, indicating that the original question was potentially imperfect/flawed: UPDATED version of the question. https://gmatclub.com/forum/two-differen ... 44340.html

siddhantvarma · Answer

Hi experts
I'm unable to understand how (A) is the right answer and not (B). Can someone please explain?

bb · Answer

Hi. At first glance, both A and B. are assumptions for the passage. Technically both can be correct but one of them is more correct than the other.

Reading the prompt can help zero in why one of the assumptions is critical to the argument while the other one is a secondary assumption necessary for the experiment.

Answer choice B is responsible for a fair experiment. Answer choice A however is stronger because it is more relevant to the discussion and more relevant to the argument.

HarshSoni890 · Answer

Option A is correct because the passage’s conclusion explicitly says that cold temperature increases the *likelihood of illness* in rabbit

Not that cold temperature *IS* the reason of illness

In this case option B might have been correct

bekhzod23 · Answer

I think B closer choice than A. As answer choice A is more likely to be a supporter rather than assumption

bb · Answer

I feel both are assumptions 😂 but answer choice a is more relevant to the core of the argument itself. But we can also negate the conclusion, To a large degree at at least. It’s not super relevant however to the argument. So A is a better answer but the B is not really incorrect the way I see it.

What is the source of the question?

What is the source of the question?

siddhantvarma · Answer

@bb If I negate A, I get "The exposure to the cold temperature did not act as a catalyst for the toxins that made more rabbits sick." Even if cold isn’t a catalyst, cold could still directly weaken rabbits’ immune systems or interact in some other way to raise illness rates. Negating A removes one possible scenario; it doesn’t undermine the broader claim that cold raises the likelihood of sickness. Whereas if I negate B, "The toxins given to the rabbits in the two cages were not of the same strength and/or not of the same amount." => The cold-temperature explanation loses its force; we no longer know whether cold or dosage caused the 75 % illness rate which breaks the conclusion.

Source: Manhattan CR Guide 6th Edition

I agree

My problem with A is that the conclusion is "The lab technicians concluded that cold temperature increases the likelihood of illness in rabbits." The conclusion says nothing about toxins, so to connect the cold temperature to toxins seems like a stretch to me when no other information is given. The cold doesn’t have to act as a "catalyst" for the toxin, it could just make the rabit ill because of the temperature. If the toxins are of different strength and amount, the whole conclusion about "temperature caused illness" breaks because now it could be a higher dose of toxin that could have killed the rabit, not the temperature

bb · Answer

Good point about not having a connection to toxins but I don’t feel we need a connection in this case because toxins are a constant.

I understand your discomfort but we already know that both received toxins and Neil the difference was the temperature in the experiment so I think it’s OK for the answer not mention toxins explicitly....

Usually Manhattan has much better questions... These are written by their own instructors for teaching purposes. I feel the question stem is a bit imperfect. I feel that if the stem was modified to ask something along the lines of which of the following could explain the reason for scientist reaching this conclusion type of thing. That would make A correct and B incorrect.

WA@pqo571 · Answer

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HRX273 · Answer

Why not E ?? Then because author already saying by exposing too the cold temp ? I am confused !!

siddhantvarma · Answer

(E) goes beyond the conclusion by suggesting even slight temperature variations cause illness regardless of cage. The experiment only tested one specific cold temperature condition. Slight temperature variations falls out of scope of the argument.

stupidscalper · Answer

It also doesn’t mention anywhere that the number of rabbits in each cage is the same. We essentially have two fractions of two unknown quantities. I honestly think this question is flawed.

bb · Answer

The fact that it does not mention that there is the same or different number of rabbits is not a flaw in this question type. Anything that is not stated can be assumed to be the same. So while one of the assumptions of the experiment is that the number of rabbits was the same, the fact that it wasn’t provided is one of the options indicates that it’s not a play here and we can assume it was the same.

APram · Answer

This question is basically strengthen or weaken test 
Conclusion is : Increase in coldness leads to sickness in rabbits

Option A:
Cold temp act as catalyst for toxins injected. If yes, this strengthens the conclusion. If no, then it weakens the conclusion
Option B:
Toxins were of same strength and same amount. If yes, then it strengthen the conclusion but if no, then we are not told any information related to this.
option C:
Injecting toxins doesn't make them sick. If this is correct then cold temp is only affecting sickness which strengthen the conclusion. If incorrect that toxins make them sick then authors conclusion is weakened that cold temp leads to sickness.

Kindly suggest why option A is better than option C based on my judgements and correct if I am evaluating it wrongly.

bb · Answer

The easiest way to eliminate this answer choice is looking at the word variations. This means raising the temperature or lowering the temperature. That’s not the case in our experiment.

Second and most important logical reason for elimination is that this choice makes infestingnjecting rabbits pointless and the whole experiment silly because if all it took was some temperature fluctuation, our conclusion falls apart. We have some of the not so smart scientists in this case.

bb · Answer

Hi. I don’t think you have read the conclusion accurately.

The lab technicians concluded that cold temperature increases the likelihood of illness in rabbits.

In this situation, cold does not make them sick by itself. Here we are told that the conclusion is that the likelihood of illness goes up when they are exposed to cold but the illness is still caused by the injection. Thus yet another unstated assumption is that cold temperature weakens the immune system or in some other way helps the virus yet is not the direct cause of the sickness.

I hope it helps.

PS. I would be a bit careful about approaching questions such as weaken or strengthen if they’re not exactly that type. It may work a lot of the times but it won’t work always.

PPS. Another perhaps reason you were thrown off by this is that I know some cultures have a strong belief that being exposed to cold or draft will make one sick while in the United States the common belief (and backed up by science quite a bit) is that microbes and viruses make one sick and if you have no viruses present in your body, no matter the cold exposure, you still will not get sick. Obviously, there is hypothermia which is a whole different condition but the person who wrote this question likely was not aware of some of the cultural differences.

Nihal840 · Answer

The correct answer is (B) The toxins given to the rabbits in the two cages were of the same strength and the same amount.

bb · Answer

B. indeed is an assumption in this argument and is needed for the validity of the experiment but B. would only be undoubtedly correct if the question was asked which of the following would make the conclusion false. Then B would win.

However, for the argument and for the logic of the argument to work, a is the better answer.

PS. I completely understand the confusion and why you’re thrown off. I tried this question in ChatGPT and it was thrown off as well.

However, the more I look at this question the more I like it. It helps you in on a very specific wording of the question and the wording of the prompt and it also helps you distinguish between situations where it’s very important to pay attention to the prompt and not to treat this question as a flaw or weak or anything else.

stupidscalper · Answer

You’re right here about the number of rabbits. Thanks for clarifying.
I still think B is the correct answer. Option A isn’t so much an assumption that the conclusion is based on as much as it is the conclusion itself. An argument could be made that option A is just the conclusion worded differently rather than it being a prerequisite assumption for the conclusion to be true.
Option B, on the other hand explicitly states something we’ve intuitively assumed. It’s better suited to be called an assumption.
It’s a tricky one for me.

Two different cages of rabbits were given injections of mild toxins. I

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