Rats, Gerbils, Mice n Hamsters

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Rats, Gerbils, Mice n Hamsters

by komal » Mon Feb 01, 2010 10:39 am
Rats are generally more active than mice. But since gerbils are generally more active than hamsters, it follows that rats are generally more active than hamsters.

Any of the following, if introduced into the argument as an additional premise, makes the argument above logically correct EXCEPT:

(A) Gerbils are generally more active than rats.

(B) Mice are generally more active than hamsters.

(C) Mice are generally more active than gerbils.

(D) Mice and gerbils are generally equally active.

(E) Rats and gerbils are generally equally active.

OA : A source : kaplan 800

p.s. these are the types of questions i have most difficulty solving. detailed explanation would be much appreciated. thx
Source: — Critical Reasoning |

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by Osirus@VeritasPrep » Mon Feb 01, 2010 10:44 am
diagram it

Rats > mice

Gerbils > hamsters

Conclusion: rats > hamsters

to make this logically correct you need to add any of the following

Rats> mice>gerbils> hamsters

Choice B states: Mice > Hamsters

Choice C states: Mice > Gerbils
Choice D states: Mice = gerbils since Rats are more active than mice, and mice are equal to gerbils, it follows that rats would be more active than gerbils.

Choice E states: rats = gerbils > hamsters

Choose A

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by Osirus@VeritasPrep » Mon Feb 01, 2010 11:06 am
To approach this question type you need to write out the relationships

Premise: Rats more active than mice
Premise: Gerbils more active than hamsters

Conclusion: Rats more active than hamsters

To prove this you need to know if mice are more active than either gerbils or hamsters since Rats are more active than mice, if mice are more active or equally active as gerbils and hamsters, it will sufficiently prove that rats are more active than hamsters. Statement A is insufficient, so it do enough to make the answer logically correct. If you are proving that rats are more active than hamsters, a statement that says that gerbils are more active than rats will not prove this. You would need more information to answer the question.

With statement B, since rats are more active than mice, and mice are more active than hamsters, it is logical to conclude that rats are more active than hamsters


With statement C, since rats are more active than mice and mice are more active than gerbils, which are more active than hamsters, it logically proves that rats are more active than hamsters

With statement D, with mice and gerbils being equally active, and rats are more active than mice, this would mean that rats are more active than gerbils. If they are more active than gerbils, and gerbils are more active than hamsters, it is logical to conclude that rats are more active than hamsters

With statement E, if rats and gerbils are equally active and gerbils are more active than hamsters, then rats would be more active than hamsters as well.

Choose A

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by gmatmachoman » Mon Feb 01, 2010 10:53 pm
Komal,

GMAC never tests on Formal Logic!!

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by bhumika.k.shah » Mon Feb 01, 2010 11:09 pm
IMO A

R>M

G>H

apply each answer options!

all will prove that R > H except A

Hope it helps! :-)

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by komal » Mon Feb 01, 2010 11:09 pm
gmatmachoman wrote:Komal,

GMAC never tests on Formal Logic!!
oh okay so i shouldn't waste time on these questions. Thats cool