mice

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mice

by pappueshwar » Tue Mar 13, 2012 7:31 am
Two groups of laboratory mice were injected with cancerous cells. One group's cages were rotated in a disorienting manner. Two-thirds of these mice developed cancers. One-tenth of the mice in stationary cages developed cancers. The researchers concluded that stress enhances the development of cancer in laboratory mice.

The researchers' conclusion logically depends on which of the following assumptions?

(a) Rotating the cages in a disorienting manner produced stress in the mice in those cages.
(b) The injections given to the two groups of mice were not of equal strength.
(c) Injecting the mice with cancerous cells caused stress in the mice.
(d) Even without the injections the mice in the rotated cages would have developed cancers.
(e) Even the rotation of cages in a manner that is not disorienting is likely to produce stress in mice in those cages.

OA IS A IF A is taken as the answer , then how will one address the issue of 1/10th of the mice in stationary cages to develop cancers using A as option
Source: — Critical Reasoning |

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by vikram4689 » Tue Mar 13, 2012 9:21 am
keyword to look for is ENHANCES, your comment would have been correct if ENHANCES in argument is replaced with DEVELOPS
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by chris@magoosh » Tue Mar 13, 2012 2:01 pm
Yes, Vikram4689 is right: the keyword is enhances. The mice already have had cancerous cells injected in them, so they will develop cancer. The issue here is the discrepancy in rates. If the funky cage orientation group has a higher rate of cancer, then perhaps the cage is to blame for the increased level. The theory the scientists have is that stress enhances the development of cancer. Not that it is the SOLE cause (remember the cancerous cell).

The connection here is between stress and funky cage orientation. For the researchers' conclusion to hold, a link must be drawn between the two----->

funky cage orientation = stress.