Critical Reasoning

The ancient Nubians inhabited an area in which typhus occurs, yet surprisingly few of their skeletons show the usual evidence of this disease. The skeletons do show deposits of tetracycline, an antibiotic produced by a bacterium common in Nubian soil. This bacterium can flourish on the dried grain used for making two staples of the Nubian diet, beer and bread. Thus, tetracycline in their food probably explains the low incidence of typhus among ancient Nubians.

Which of the following is an assumption on which the argument relies?

A. Infectious diseases other than typhus to which the ancient Nubians were exposed are unaffected by tetracycline.
B. Tetracycline is not rendered ineffective as an antibiotic by exposure to the processes involved in making bread and beer.
C. Typhus cannot be transmitted by ingesting bread or beer contaminated with the infectious agents of this disease.
D. Bread and beer were the only items in the diet of the ancient Nubians which could have contained tetracycline.
E. Typhus is generally fatal

OA is B. it sounds fine and a common protector answer type.

But I believe E is an assumption that author would have made before he thinks of B. Isn't the author assuming in first place that the skeleton found are of people who died of the disease ? If not, then all theory he has come up with might not be true as he has assume that the effects of that disease remain through out one's life on his body.

Easy -

Glad to see that you are ready to anticipate the answer on this one. I agree that the official answer is what would be expected for this type of assumption.

Let's talk about E. E would not be a required assumption - unless you make several assumptions yourself!!

Does Typhus need to be generally fatal in order to leave, as you put it, "effects of that disease remain through out one's life on his body."? Think of broken bones that people have throughout their lives - these leave marks that can be seen after death yet are usually not fatal. Or how about the disease polio - I know that it did cause deaths but certainly below 50%? Or even dental records?

I also do not see a reason to assume that the author believes that the people died of the disease. It does not say this, so you would need to assume it. Perhaps the people died of all sorts of things and this study just happens to focus on the fact that they did not get typhus.

I am not saying that typhus is not generally fatal. I actually have no idea. But from what we have in this argument that is not a requirement for this conclusion.

David : thanks a lot. i did think over it, sounds good. point noted.

Another quesion from Manhattan CAt :

Country X imposes heavy tariffs on imported manufactured goods. Company Y has determined that it could increase its profits in the long term by opening a factory in Country X to manufacture the goods that it currently produces in its home country for sale in Country X.
For Company Y's determination to be true, which of the following assumptions must also be true?

(A) Company Y will be able to obtain all the necessary permits to open a factory in Country X.
(C) A sustainable market for Company Y's goods currently exists in Country X.

OA is C. Sounds ok.

Why A is wrong?

[spoiler]Explanation regarding (A): While this is a tempting answer, it is not necessary to assume that Company Y will be able to obtain all necessary permits. The conclusion does not indicate whether Company Y will actually be able to implement the plan, only that the plan could increase profits if implemented.[/spoiler]
I agree when such condition is already given( if factory is opened) , then we can't make it an assumption. however, I do not think this is worded in same way.

Could you share your thought please.

I have to agree with you. That takes the assumption a little too far and would not appear this way on the GMAT - probably not even the LSAT.

In fact, I am not in love with choice C. Why does a sustainable market have to currently exist? What if a sustainable market will exist in 6 weeks from now? The determination is about long-term markets. C would be better if it said, "A sustainable market for company Y's goods will eventually exist" or "it is possible for a sustainable market to exist."

I agree with what you say about A. What good is it to decide that you would make a profit if you can do something that you cannot do? What if I say "nuclear fusion could solve our energy problems." Then an assumption is "nuclear fusion is possible." I think that is a reasonable assumption.