LSAT-2-4-22

flywood

22. All intelligent people are nearsighted. I am very nearsighted. So I must be a genius.

Which one of the following exhibits both of the logical flaws exhibited in the argument above?

(A) I must be stupid because all intelligent people are nearsighted and I have perfect eyesight.

(B) All chickens have beaks. This bird has a beak. So this bird must be a chicken.

(C) All pigs have four legs, but this spider has eight legs. So this spider must be twice as big as any pig.

(D) John is extremely happy, so he must be extremely tall because all tall people are happy.

(E) All geniuses are very nearsighted. I must be very nearsighted since I am a genius.

毫无疑问,D是最好的答案,可是我觉得B似乎也可以,为什么把B排除?

kingsoft

     i  was also confused by the choice B

     now,  i encounter this problem for the third time, and i already knew the answer  

      Thus,  i pay very attention to the difference between choice B and D

     i found that as "genius" corresponds to "intelligent", "extremely tall" corresponds to "tall"

    but choice B does not indicate this flaw

    to be careful of the question:"...exhibits both of the logical flaws... "

    i think this flaw is the difference between B and D

Bensontuo

kingsoft 发表于 2004-8-10 23:51
     i  was also confused by the choice B     now, ...

Spot the question types: Methods of the reasoning - Parallel Flaws.

A ---> B ( falsely assume A --- C )。So, B ---> C

Answers:

A. A ---> B, So No B ---> C ( Falsely assume No A ---> C )

B. A ---> B , B ---> A

C. A ---> B, C ---> D, Cd ---> 2Ab

D. A ---> B, C ---> B, So, A ---> C

E. A ---> B, So, A ---> C

No doubt, D is the best answer